As the waste of the animal powers is
again restored by sleep, so in like manner the in-
cessant loss of the natural powers, and even of the
very elementary parts of the body, is repaired by
fresh and repeated supplies of food.
To the acquisition and use of this food we are
forcibly led by the frequent and irresistable calls
of nature. These calls, though widely different
from each other in their natures, tend notwith-
standing to the final accomplishment of the same
end: they consist, on one hand, of the insupport-
[Seite 2] able torments of hunger and thirst; and on the
other, of the very pleasing, but no less powerful,
allurements of appetite.
The stimulus of hunger, some physiologists have
sought for in the mutual friction between the rugae
of the stomach when empty; others in that which
appears, indeed, to be of primary importance in
giving birth to this potent sensation, namely, not
only in a more copious secretion and afflux of the
humours discharged into the first passages, more
especially of the saliva, the pancreatic juice, and
the bile, but also in a certain degree of morbid
acrimony, with which these same humours are apt
to be contaminated, unless such a state be guarded
against by regular supplies of nourishment.
Thirst is a distressing sensation, arising princi-
pally from a very troublesome dryness of the fau-
ces and esophagus; and also from a peculiar im-
pression produced by taking in acrid, but more
especially saline, substances.
With respect to the absolute necessity of satisfy-
ing and removing these stimuli, no fixed and posi-
tive rule can with propriety be laid down, as such
[Seite 3] necessity is doubtless rendered more or less urgent
by varieties in age, habit of body, and more espe-
cially by the power of custom. From a general
consideration of this subject, however, the result
appears to be, that an adult and healthy person,
who is under no undue impressions or influence,
(in whom, for instance, those assuasive calls of na-
ture are neither silenced by the louder ravings of
enthusiastic fanaticism, nor by other preternatural
causes) cannot refrain from the use of food, for
even one whole day, without a very great prostra-
tion of strength; and can seldom fast for more than
eight days without incurring the utmost hazard of
life.
With regard to drink, although a desire for
this appears to urge with the greater vehemence
and intensity of the two, it is, notwithstanding,
much less necessary to life and health than the ar-
ticle of food. This we infer, with apparently
strict propriety and truth, not only from numerous
species of warm-blooded animals, as mice, quails,
&c. that are never impelled by necessity to the use
of drink, but also from actual examples of certain
individuals of the human race, who have conti-
nued, through a long series of time, in the enjoy-
ment of life, health, and spirits, without recourse
to the use of drinks of any kind.
As to food, controversies have existed respecting
the kind most proper to satisfy the internal calls
of our nature: whether, for example, the struc-
ture and constitution of the human body corres-
pond most perfectly with food taken from the ani-
mal, or with that derived from the vegetable,
kingdom; and which of these two kinds of sub-
stances nature, therefore, designed to constitute
the aliment of man?
That man is by nature an herbivorous animal,
Rousseau attempted, with a great degree of acute-
ness, to prove, not only by arguments taken from
the figure of his teeth, and the length of his in-
testines, but by the further consideration, that wo-
man is naturally uniparous, and furnished with
two mammae, &c.; to all which might be added,
actual examples of rumination having been per-
formed by human subjects, a process well known
to belong exclusively to herbivorous animals.
Those, on the contrary, who, with Helvetius,
consider man as a carnivorous animal, attempt to
support their opinion by the shortness of his intes-
tinum caecum, and other arguments of a similar
nature.
But from more accurate observation, and a
more minute investigation of the subject, it ap-
pears, that nature did not intend to restrict man
to the exclusive use of either the one or the other
of those kinds of aliment, but more indulgently
destined him to a free participation of both. That
this is indeed the kind destination of man with re-
spect to the nature of his food, we very naturally
infer from his teeth, especially the molares, and the
conformation of his intestines, briefly mentioned
above, possessing a middle state between the same
parts, as they exist in carnivorous and in herbivo-
rous animals. This prerogative of man is, how-
ever, still more forcibly demonstrated, by the na-
ture of the articulation which connects the con-
dyles of the lower jaw to the ossa temporum in hu-
man subjects.
If the observations be true (and they surely
cannot be doubted) which we stated on a former
occasion, respecting the high privilege of man, in
being by far better calculated than other animals
for traversing an extensive range of climate on
the globe we inhabit, it from thence spontane-
ously follows, that he would have been indeed
very illy accommodated, in being solely restricted
either to the one or the other of the above kinds
[Seite 6] of food: for as some regions of the globe afford
animal, and others vegetable food alone, the ob-
vious and unhappy result of such an exclusive re-
striction would have been, that man, though cal-
culated and destined to reside in all latitudes of
the earth, must, notwithstanding, in some of them,
be denied the use of such aliments as nature had
rendered essentially necessary to the continuation
of his existence.
Of all animals, with which we are in any mea-
sure acquainted, man may, with the strictest pro-
priety and truth, be said to be omnivorous. As
on the one hand he is calculated to banquet in
luxury, amidst the most profuse variety of delica-
cies that art can prepare from the immense re-
sources of the animal and vegetable kingdoms,
so, on the contrary, he is able to retain his health
and vigour when subsisting on the most simple and
frugal fare.
Thus, to produce only a very few examples, a
great many men even at the present day subsist
solely on a vegetable diet, such as potatoes, ches-
nuts, dates, &c. which constituted also the food of
the first progenitors of the human race: for it ap-
pears highly probable, that those simple and hardy
sons of nature, supported life first by the fruits and
[Seite 7] roots of plants, and afterwards, by the more sub-
stantial and durable fare of grains and pulse.
Some of the Moorish tribes in Africa live almost
entirely on the gum senegal.
The inhabitants of Kamschatka and of a great
many other maritime situations subsist on fish.
In Europe itself, the Morlachi are supported al-
most entirely on a diet of flesh.
Some nations of Barbarians subsist even on raw
flesh, a circumstance which is undoubtedly true,
with respect to the Samoids, the Esquimaux, and
certain tribes of people inhabiting South America.
Neither are the liquids made use of as drinks,
in certain nations, less singular and striking.
Thus the inhabitants of several islands, which
lie between the tropics, more especially those situ-
ated in the Pacific Ocean, are entirely destitute of
sweet and pleasant water, and therefore, as a sub-
stitute for this fluid, use the delicious juice of the
lactescent cocoa.
Others again drink the waters of the briny
ocean; – from all which facts and circumstances,
[Seite 8] taken collectively, together with an infinitude of
others that might be adduced, we need not hesitate
a moment to pronounce, that man is literally an
omnivorous animal.
For the purpose of masticating the
more solid species of food, both our under, and
upper jaws, are armed with three different kinds
of teeth.
These are first, the incisores, which, in most
men, are chisel-formed, and well calculated to bite
off morsels of food.
Secondly, the canini, strong, conical and com-
pletely adapted for breaking substances of greater
firmness.
And lastly, the molares, of different sizes, exqui-
sitely fitted for the process of grinding.
The mandible or lower jaw is connected to the
other parts of the head, by means of a very singu-
lar variety of articulation, which appears to be of
a middle nature between arthroida and ganglimus.
Being furnished with a pair of double concave car-
tilages, it thus unites, to a sufficient degree of
strength and firmness, a capacity of being easily
and very considerably moved in all directions.
The under jaw is drawn back, in opening the
mouth, chiefly by means of the musculus biventer,
but in part also by the geniohyoidei and the my-
lohyoidei.
It is brought back again, when we attempt to
cut any thing through with the dentes incisores,
and pressed with astonishing force against the
opposite jaw, during our efforts to crush any
hard substances, by the masseter and temporal
muscles.
It is moved laterally in chewing, by the action
of the internal and external pterygoid muscles;
the latter of which have also the power of moving
it in a forward direction.
Substances taken into the mouth for the pur-
pose of being chewed, are retained, placed in a
proper situation, and thus effectually subjected to
the action of the teeth, by means of the musculus
buccinator, and the tongue, an organ of extreme
flexibility, and very capable of changing its form
(§ 233).
During the act of manducation we emulge, as
it were, a certain quantity of saliva, which is an
aqueous liquid, of a nature somewhat saponace-
ous; it contains a small quantity of earthy matter,
(which gives origin to tartarous incrustations of
the teeth, and to small sublingual calculi); this
fluid, from being in perpetual contact with the
tongue, makes no sensible impressions of taste on
that organ, although it contains a small quantity
of microcosmic salt; it possesses antiseptic and re-
solvent properties, and has also a power of spee-
dily exciting the process of fermentation in vege-
table substances, especially in those of the farina-
ceous kind.
The sources from whence this fluid is derived
are, small conglomerate glands, of three several
[Seite 11] orders, the lateral and internal, of which are situ-
ated beneath the lower jaw.
The most considerable of these glands, called
parotids, (remarkable, on account of being ex-
tremely subject to metastases), excrete their saliva
through the Stenonian duct, just behind the middle
molar tooth of the upper jaw.
The saliva furnished by the submaxillary glands,
is discharged through the duct of Wharton.
That derived from the sublingual glands, which
are the least of all, flows through the numerous
ducts of Rivinus.
The excretion of saliva, (of which, in confor-
mity to the opinion of Nuck, about a pint is com-
monly supposed to be secreted in the space of
twelve hours), is considerably encreased both by
the application of any stimulating substance, and
also by mechanical pressure, the latter of which
appears to act merely by emulging the containing
parts.
Thus, whatever hard substances we chew, be-
come perfectly moistened and macerated, as it
were, by a copious afflux of saliva produced in
[Seite 12] consequence of the pressure, to which the parotids
are particularly exposed from, being situated so
near to the articulation of the lower jaw.
With regard to the operation of stimuli on the
secretion of this fluid, it is necessary farther to ob-
serve, that when acrid substances are taken into
the mouth, a plentiful afflux of saliva is immedi-
ately produced, which has the effect of diluting
and thus effectually counteracting the irritating
acrimony: an increase of the same fluid is also oc-
casionally produced by the stimulus of the imagi-
nation; to this cause must we refer that afflux of
saliva, which so frequently accompanies a strong
appetite for food.
With the saliva are blended a fine aqueous,
dew-like fluid, which transudes from the soft parts
of the mouth, and also a mucus, secreted by small
glands, situated in the lips and cheeks: it is a
portion of this mucus by which the tongue is lu-
bricated.
The morsel during mastication, being thorough-
ly moistened by this mixture of saliva and other
animal juices, is thus, not only converted by de-
grees into a soft pulpy bolus, more fit for the pur-
[Seite 13] pose of deglutition, but is likewise prepared, at
the same time, for further digestion and final assi-
milation.
The actual business of deglutition, although it
appears to be of a very compound nature, and is
indeed performed by the co-operation of a great
many different parts, may be considered as com-
mencing and proceeding in the following order;
viz. the tongue being first retraced towards its
basis, and becoming therefore somewhat turgid
and stiff, receives on its excavated dorsum or back,
the lubricated and moistened bolus, which is from
thence forced onwards into the fauces, where it
is received by the expanded infundibulum of the
pharynx, which appears, at the same time, to ad-
vance somewhat upwards; on the reception of the
food the infundibulum makes a singular and vio-
lent exertion, which may be supposed to proceed
from a species of vita propria; from this funnel-
like entrance, the bolus is again protruded on-
ward, by a threefold contraction of the pharynx,
into the aesophagus. All the above motions suc-
ceed each other with the utmost degree of rapidi-
ty, and are of extremely short continuance.
For the purposes of expanding this passage, and
rendering it at the same time steady and secure,
[Seite 14] nature has made the most ample provision by a
variety of auxiliary parts.
The motion of the tongue, in this momentous
business, is regulated and directed by the os hyo-
ideum.
To prevent any of the substances swallowed,
from passing, by mistake, either into the internal
nares, or into the eustachean tubes, the soft palate
is very wisely provided. This fleshy curtain, de-
pending equally from the arched roof to which it
is attached, is capable of being rendered tense by
the action of a peculiar set of muscles, and thus
the above passages may be completely closed.
The glottis is securely guarded by the tongue
itself, because at the very instant in which we at-
tempt to swallow, the larynx, being drawn up-
ward and forward, is in a certain degree concealed
beneath the retraced basis of the tongue, and is
so compressed by it, that the glottis, not only by
this constriction, but also by the additional security
of the epiglottis, is thus very effectually guarded
against the intrusive entrance of any heterogene-
ous substances.
Finally, the business of deglutition is greatly fa-
cilitated by means of a quantity of mucus, with
[Seite 15] which the whole of the passage above described
is lubricated; and which, besides the lingual
glands already mentioned (§ 235), is chiefly fur-
nished by the numerous sinuses of the tonsils, and
by that infinitude of mucaginous cryptae, so pro-
fusely bestowed on the larynx itself.
With respect to the oesophagus itself, through
which all substances swallowed must necessarily
pass, previously to their entrance into the stomach,
it is a fleshy canal, rather narrow in its diameter,
and exceedingly firm and strong, but at the same
time pliable, dilatable, and possessed of a high degree
of sensibility: it is composed of tunics or coats,
which, if we except the difference in their thick-
ness, bear no small resemblance to the coats of the
other portions of the alimentary canal.
Thus, the external covering is muscular, made
up of fibres running both longitudinally and in
transverse or circular directions.
The middle coat is nervous, ending on each side
in a very lax cellular membrane, by means of
which it is connected, as well to the preceding, as
to the subsequent tunic.
Lastly, the internal coat is lined by mucus of an
exquisite degree of lubricity.
The following appears to be the mode in which
this canal performs its office; as soon as it has re-
ceived either a draught or bolus completely within
its parietes, the parts immediately above presently
contract themselves, thus forcing downwards the
substance to be swallowed; which, if it be a bo-
lus, can be protruded onward only by one uni-
form series of exertions in the surrounding tube,
till it has passed through the diaphragm, and been
finally received into the cavity of the stomach
itself.
The chamber, or immediate seat of di-
gestion, is the stomach, a viscus more uniformly
possessed than any other, by almost every indivi-
dual throughout the immense range of animated
nature: if, therefore, we estimate the dignity of
the several viscera from this circumstance alone,
the stomach is, doubtless, to be considered as an
[Seite 17] organ surpassing all the others in utility and im-
portance to the animal economy.
The human stomach resembles a leathern pouch,
of very considerable dimensions, sufficient, for the
most part, in an adult, to contain three pints, or
more, of water, and furnished with two separate
orifices or mouths:
These are, first, a superior orifice, called car-
dia, which is formed in the place where the oeso-
phagus, by a plaited and somewhat oblique aper-
ture, opens into the stomach itself, and points to-
wards the bottom of this viscus, or that extremity
which regards the left side of the body.
Secondly, an inferior one, which constitutes the
termination of the right, and less capacious end of
the stomach: this orifice is called pylorus, and de-
scends a short distance into the cavity of the ad-
joining duodenum.
The situation of the stomach, when empty, is
different from that of the same organ, when full:
thus, in the former state, it hangs loose and flaccid
in the abdominal cavity, in such a manner that its
greater curvature looks in a backward direction;
[Seite 18] and its pylorus, being turned somewhat upwards,
forms a plaited or twisted angle with the duode-
num, to which it is connected.
But in the latter state, when distended with food,
its greater curvature is again turned, and looks in
an anterior direction, so that the pylorus enters
now, by a more direct route, into the duodenum;
whereas the cardia, on the contrary, is so folded
and bent as to be completely closed.
The stomach is composed of four principal
coats, distinguished and separated by three others,
of an entirely cellular nature, which lie between
them.
The most external of these coverings is common
to the stomach, with all the rest (save a small por-
tion) of the alimentary canal, and is continued
over the omenta, which shall be spoken of here-
after.
Next to this, lies that cellulo-muscular coat, so
very striking in its nature and properties, on which
depend both the exquisite irritability of the sto-
mach (§ 306.), and also its peristaltic motion; the
latter of which shall be a subject of consideration
in another place. This coat is composed of dif-
[Seite 19] ferent strata of muscular fibres, which are usually
divided into three orders, one longitudinal, and
two circular; the circular fibres are again divided
into those that are directly, and those that are ob-
liquely, circular. It must, however, be observed,
that so extremely variable and irregular are the fi-
bres of this coat, with regard to their direction
and distribution, as scarcely to admit of reduction
to, and arrangement under, any determinate and
general rules.
The third principal coat is called the nervous,
an appellation extremely improper, as it is compo-
sed wholly of condensed cellular membrane, be-
coming gradually more soft and lax on each side;
by which means it is connected externally to the
muscular, and internally to what we shall presently
call the villous, coat. It is, notwithstanding, so
firm and robust, that it may be aptly enough call-
ed the basis of the whole stomach.
Lastly, the internal coat, which has been very
improperly called villous, is exceedingly tender,
somewhat spongy, porous, and folded into a very
great number of rugae or wrinkles, so that its area
is much more extensive than that of any of the
other coats which we have just described: it every
where exhibits cells of the utmost minuteness, some-
[Seite 20] what similar in appearance to those larger ones,
with which the reticulum of ruminating animals
is very beautifully and elegantly characterized.
The internal surface of this coat is lined with
mucus, apparently secreted by small mucaginous
cryptae, some of which may be, indeed, readily
enough distinguished near to the pylorus, or lower
orifice of this organ.
The stomach is furnished with an astonishing
apparatus of nerves, whence its sensibility is so ex-
quisite, that it is capable of being very readily af-
fected by stimuli of almost every kind, whether
they be external, as cold &c. or internal as food,
and even by the inquiline humours themselves.
From the same source arises also that extensive,
and truly admirable consent, which exists between
this important viscus and most of the other func-
tions of the body; to which head belongs, in a
particular manner, the striking effects, produced
on the stomach, by all mental commotions, and
also, on the other hand, the very powerful influ-
ence of an entirely sound and healthy state of this
organ, on the cheerfulness and serenity of the
mind.
The number and functions of the blood vessels,
belonging to the stomach, are no less considerable
and striking, than those of the nerves. The small
arteries, (of which an infinitude of different or-
ders, are minutely interspersed throughout the cel-
lular coats of this organ), appear to constitute the
immediate sources of the gastric juice, a liquor
which flows in perpetual streamlets from the inter-
nal surface of the stomach.
This juice bears, on the whole, no small resem-
blance to saliva, except that, agreeably to the ex-
periments of the illustrious Spalanzani, its powers
are counter to those which promote fermentation.
As to the rest of its properties, it is saponaceous,
equally antiseptic with the saliva, and is indeed, a
very powerful menstruum, sufficient gradually to
dissolve milk after it has been gently coagulated in
the stomach.
The gastric juice appears to be the most power-
ful and active agent in the great business of diges-
tion. If the food be carefully masticated, and suf-
ficiently blended with the menstruum furnished by
the salivary glands, this fluid of the stomach com-
[Seite 22] pletely dissolves, and finally converts it, into a
soft pultaceous chyme.
This momentous function is also further aided
and promoted, by a variety of accessory and assis-
tant powers: of these the most considerable is the
peristaltic motion, by means of which the food,
now reduced to a pulpy consistence, is thoroughly
agitated, and kept perpetually in a state of wavy
commotion. Although the force of the peristaltic
motion fall far short of the chimerical calculations,
formerly made on this subject, by mathematical
physicians, and although it be not itself the sole
cause of digestion, it is, notwithstanding, of the
utmost efficacy and influence in this important
process.
Among the auxiliary powers, of this kind, may
be also reckoned another species of motion, which
the pressure of the surrounding parietes of the ab-
domen, communicates to the stomach: to these
we may still farther subjoin, the extreme warmth
of the situation in which this viscus is placed; so
very powerful was this fotus or bath, formerly
esteemed, in consequence of the abundant quan-
tity of blood contained in the neighbouring vessels
[Seite 23] and viscera, that instead of the term digestion,
that of coction, was used by the greater part of
physiologists.
To determine, with precision, the period of time
requisite for the conversion of our aliment into
chyme by the joint co-operation of the foregoing
powers (§ 361.), will appear almost impossible to
any one, who may consider the great variety of
circumstances, on which such conversion must de-
pend: these circumstances are, the quality and
quantity of the food taken in, the different degrees
of force in the digestive powers, the greater or
less attention and care bestowed on the prepara-
tion of the food for digestion, by previous masti-
cation, &c.
For in a healthy subject, the unimpaired sto-
mach does not discharge such alimentary matters
as have been taken in, previously to the conver-
sion of their digestible parts into a perfect pulp.
From whence it is evident, that different periods
of time are requisite, for the complete digestion of
different kinds of food. If, however, it be allow-
able to form any general conclusion on this subject,
it would appear, that from the third, to the sixth
hour, after the use of aliment, the stomach has,
for the most part, discharged through the pylorus,
[Seite 24] in a very gradual manner, the whole of its pul-
taceous contents.
The pylorus is an annular rim, not formed,
(like the other rugae on the internal surface of the
stomach), by the folding of the villous coat alone,
but consisting, in part, also of a few fasciculi from
the subjacent nervous, and also of certain fibres
from the muscular, coat: all which parts are so
organized and arranged, as to constitute a coniform
termination to the stomach, that is extended into,
and embraced by, the duodenum, in the same
manner as the os uteri is received and embraced,
by the superior part of the vagina.
Subsequent to the expulsion of
the chyme through the pylorus, that pulpy mass
must be subjected, in the duodenum (a short, but
remarkable portion of the intestinal tube), to new
and considerable changes, previously to the for-
[Seite 25] mation and final separation of complete, alimen-
tary chyle. These necessary changes are effected
in the chyme by the accession and admixture of
various kinds of inquiline humours, the most strik-
ing and important of which, are, the bile and the
pancreatic juice.
Of these two humours, we will speak in sepa-
rate sections. We proceed therefore, to consider
the liquor of the pancreas first, because it appears
to bear a very considerable resemblance, both in
its nature and uses, to those other two dissolvent
humours, of which we have already spoken, name-
ly, the saliva and the gastric fluid.
Athough it be indeed a matter of no small diffi-
culty, to procure the pancreatic liquor of a sound
animal, in a pure and unadulterated state, yet the
obvious and unequivocal result of all the facts,
which the most attentive investigation has been
able to supply, with regard to its nature, is, that
it bears the strongest similitude to the saliva in all
its general properties. Were it not for the pur-
pose of showing how mischievous, and even de-
structive, the practice of medicine may become,
unless directed by sound principles of physiology,
I should not think it necessary nor even proper, at
[Seite 26] the present enlightened period, to mention the er-
roneous physiological hypotheses, entertained by
Franc. Sylvius, and his humble followers, Regn.
de Graef, Flor. Schuyl, and others, respecting
the visionary or supposed acidity of the pancreatic
liquor, especially as those opinions have been long
since very ably refuted by Pechlin, Swammerdam,
and Brunner, characters of the first celebrity in
the annals of medical science.
The sources from whence the lymph and saliva
are derived, bear no small resemblance to that
which constitutes the subject of our present consi-
deration, namely, the pancreas: this latter is by
far the largest of all the conglomerate glands of
the human body, and exhibits, in the whole of its
structure, a very striking similitude to the glands,
that give birth to the salivary fluid; with these
last mentioned bodies it also further agrees, in this
particular, that its excretory canals, arising from
radicles of the utmost minuteness, run together
and unite by degrees, till they constitute finally a
common duct, which has received its name from
Jo. G. Wirsung, who first discovered and de-
monstrated it in the human subject, in the year
1642.
This duct passes through the coats of the duo-
denum, and by a constant stillicidium, weeps into
the cavity of that intestine, the fluid it had receiv-
ed from the gland to which it is appended.
Finally, the excretion of this fluid appears to be
promoted by the very same powers, which were
formerly said to be subservient to the excretion of
saliva, namely, pressure and stimulus.
By means of the former, it is emulged chiefly
when the stomach is distended and rests immedi-
ately on the pancreas.
The substances that contribute most, by their
irritations, to excite a discharge of the pancreatic
fluid are, first, the chyme itself, as it passes through
the pylorus in a crude and unassimilated state; and
secondly, the bile, which is discharged through
the very same orifice with the liquor of the pan-
creas.
The use of this fluid is doubtless to dissolve the
chyme, more especially that part of it, which has
not been sufficiently digested in the stomach: by
its abundant afflux, it contributes to assimilate this
[Seite 28] pulpy mass still more and more to the nature of
the inquiline humours, and thus finally mature it
for the further process of chylification.
The secretion of bile is the pecu-
liar destination of the liver, the largest and most
ponderous viscus in man. This superiority of size
is more especially observable, during the foetal
[Seite 29] state, in which, the younger the foetus the greater
is the proportional magnitude of the liver, when
compared with that of the other viscera of the
[Seite 30] body. The dignity and high importance of this
viscus in the animal economy may be fairly de-
duced, from the universality of its presence; thus
[Seite 31] in all animals possessing red blood, it exists no less
generally and uniformly than the heart itself.
The substance of the liver is of a nature, sui
generis, and may be readily distinguished, at first
[Seite 33] fight, from that of all the other viscera of the
body: it consists of a parenchyma of a well known
colour and very tender texture: this parenchyma
is abundantly supplied with nerves, with lympha-
tic vessels (very visible on both surfaces), with bi-
liferous ducts, and finally with blood-vessels, from
whence these ducts originate: with respect to
these blood-vessels, some of which are remarkably
large, we will immediately state a few observations
on each of their several orders.
The first vessel which here presents itself for
our consideration is, the vena portarum, which
differs very widely from every other portion of
the venous system, not only in its singular appear-
ance, but also in the peculiarity of its course and
distribution, of which a few words were spoken
on a former occasion (§ 87). This large vessel
is formed by the conflux of by far the greater
number of the venous branches that originate and
run from the viscera, situated in the lower part of
the abdomen, and is invested and strengthened by
[Seite 34] a cellular covering, commonly known by the name
of capsula Glissonii. No sooner does this trunk
make its entrance into the liver, than it is divided
into several branches, which as they run in vari-
ous directions through its substance, suffer still far-
ther divisions, till they are finally encreased to a
countless number of the most subtle ramifications,
which pervade, with the utmost minuteness, every
portion of this viscus. This whole system of the
vena portarum was formerly compared, by Galen,
to a tree, the roots of which are dispersed through-
out the whole cavity of the abdomen, while its
branches are enclosed in the more contracted vo-
lume of the liver.
Another blood-vessel of a different kind, with
which the liver is furnished, is the arteria hepatica.
This vessel originates from the caeliac artery, and
although far inferior to the vena portarum, both
in its capacity and in the number of its branches,
is, notwithstanding, divided into ramifications of
astonishing subtility, and is also distributed with a
great deal of minuteness throughout every part of
the liver.
The extreme terminations of both the forego-
ing kinds of vessels, end in genuine veins, which
[Seite 35] gradually uniting, form by their general conflux,
certain large venous trunks, that lose themselves
finally in the inferior vena cava.
Those extreme terminations, by which these
small branches of the vena portarum and arteria
hepatica become radicles to the vena cava, form
a very subtle vascular texture, exhibiting a singu-
lar and striking appearance, as if the vessels were
convoluted, or wound up into globes of incon-
ceivable minuteness. These globular bodies im-
posed so effectually on Malpighi, as to induce that
illustrious physiologist to consider them as glandu-
lar, hexagonal, and hollow kernels, destined to
constitute the immediate chambers of secretion.
From those same globular convolutions of blood-
vessels arise, lastly, the pori biliarii. These are
very tender ducts, which convey the gallish liquid
from the blood, and completely eliminate the same
from the system of the liver, through the ductus
hepaticus communis, a canal which they form by
their general conflux.
It is common for physiologists to enquire,
from what kind of blood the bile is immediately
[Seite 36] secreted; whether from arterial, or from that con-
tained in the vena portarum?
Although the former of these opinions appears,
on the first view of the subject, to be rendered
most probable from the analogy of other secre-
tions, which are evidently the result of arterial
action, yet from a more accurate investigation of
the matter we will readily be convinced, that by far
the greater part, if not indeed the whole, of the bi-
liary secretion, is derived from the vena portarum:
the blood of this vessel being lurid, and highly im-
pregnated with phlogiston, corresponds precisely
with the nature of the bile; but how extremely
different, on the other hand, are the habit and
constitution of the florid and fiery arterial blood,
which the caeliac artery transmits from the aorta
immediately to the liver!
With respect to arguments drawn from analogy
we may observe, that as the vena portarum is sub-
jected to an arterial distribution, so it may, in like
manner, possess the power of performing an arte-
rial function: this same opinion, for which we con-
tend, appears also to derive additional support
from the analogy which exists between the liver
and the lungs: to perform the leading function of
these last mentioned viscera, is doubtless the imme-
diate destination of the large pulmonary arteries;
[Seite 37] whereas, on the other hand, the bronchial artery
is only subservient to the nourishment of the parts,
on which it is distributed: – the discharge of an
office, similar to this latter, is also, if we be not
greatly deceived, the more immediate destination
of the arteria hepatica. Notwithstanding what
we have here advanced, we are still ready to ac-
knowledge, that the hepatic artery may possibly
contribute somewhat towards the secretion of bile;
but, that its influence, in this respect, is indeed
very inconsiderable, and not yet sufficiently ascer-
tained and demonstrated, are positions to which
we subscribe with the utmost confidence.
The biliary hepatic liquor, when once secreted,
flows in a gentle but uninterrupted streamlet
through the hepatic duct; and, when the intesti-
num duodenum is empty, glides directly onward,
through the common ductus choledocus, into the
cavity of that viscus; but when the duodenum is
distended with chyme, it becomes necessary for
this fluid to pursue a different route, whence it
regurgitates from the hepatic, and flows through
the cystic duct into the gall-bladder, where it is
retained a certain time, and thence derives the
name of cystic bile.
The gall-bladder is an oblong sack, somewhat
pyriform in its figure, attached to the concave su-
perficies of the liver, and composed of three mem-
branes or coats.
These are, first, the external, which does not
invest the whole of the cyst, and is derived from
the peritoneum.
Secondly, the middle, usually called the nervous
coat, which, as in the stomach, the intestinal tube
and the urinary bladder, constitutes here likewise
the principal part of the tone and firmness of the
sac.
And, lastly, the internal, which bears a certain
similitude to the internal membrane of the stomach
(§ 359.); like that it is interspersed with an infi-
nitude of minute blood-vessels, and like that it is
also marked by rugae or wrinkles, which form,
here and there, fine net-like checkerings, that ex-
hibit the appearance of the most exquisitely ele-
gant lattice-work.
The neck of the gall-bladder is conical, and
forms, by its termination, the cystic duct, which
[Seite 39] pursues not a direct, but somewhat circuitous or
serpentine route, and is furnished with a few mi-
nute valves of a lunated or falciform figure.
The gall-bladder retains the bile, when once
received, till that liquor either flows out spontane-
ously, in consequence of being favoured by a re-
clined and somewhat supine position of the body,
or till it is emulged from the cyst by the pressure
of the neighbouring intestines, namely, the jeju-
num and ileum, or by the occasional passage of
hardened faeces through the transverse colon.
Different stimuli acting on the duodenum have
also the effect of soliciting a more copious effusion
of bile into the cavity of that intestine.
The remarkable contractility of the gall-blad-
der, evidenced and satisfactorily established by live
dissections and certain pathological phenomena,
(although this sac be indeed completely destitute
of all genuine irratibility), (§ 307.), will appear
to contribute, not a little, to the excretion of the
bile; especially when we consider the stimulant
impression which this fluid, after retention in the
cyst, must make on its surrounding parietes or
walls.
For although the cystic exhibits, in its general
properties, the most striking similitude to the he-
patic bile (§ 382.), it is notwithstanding concen-
trated, as it were, by rest and stagnation, and
thence rendered more tenacious and bitter: this
effect appears to be owing, in a particular man-
ner, to the lymphatic vessels of the cyst, which
slowly absorb the aqueous parts of the bile, while
thus enclosed and retained in a quiescent state.
We proceed now to the consideration of the
bile itself. This is an animal fluid of the highest
dignity and importance in the living system: its na-
ture and uses have, for twenty pears past, laid a
foundation for more literary controversies among
physiologists, than have existed respecting any
other fluid that belongs to the body of man.
What we shall advance on this subject will re-
late immediately to the cystic bile, as this is to be
esteemed the more perfect of the two, and is there-
fore in a state more favourable for successful in-
vestigation.
Bile, taken from the recent corpse of an adult
subject, who had not previously laboured under
[Seite 41] any disease, is a liquor somewhat viscid, of a faint
green colour, inclining towards a brown, inodo-
rous, and, if compared with the gall of brutes, of
a slightly bitterish taste.
Although the constituent parts of this fluid nei-
ther separate from each other spontaneously, nor
yet by so simple a mode of treatment as is sufficient
to produce that effect on the parts that compose
the blood, they may, notwithstanding, be subject-
ed, without much difficulty, to such an examina-
tion as will make it appear, that they doubtless
possess and exhibit a certain analogy to the ele-
mentary parts of the blood, though this analogy
should not be pursued to too great an extent.
The bile contains, in the first place, an aqueous
menstruum, which has been denominated by some
late physiologists, its salivary part: this may be
aptly enough compared to the aqueous portion,
and resembles also, though not in every particu-
lar, the serum of the blood.
From the bile we can also separate and procure
a small portion of a white and grumous substance,
which may be said to possess a certain, though re-
mote resemblance to the plastic lymph of the
blood.
Finally, the most striking and important princi-
ple which the bile contains is the matter of phlo-
giston, derived in large quantities from the blood
of the vena portarum, which is highly impreg-
nated with this subtle element.
This active inflammable part evidently manifests
its existence in dried bile, but more especially in
gall stones, by bursting immediately into flame,
when placed in contact with a burning substance.
To the action and influence of this principle must
we attribute those striking and singular qualities,
formerly enumerated, such as colour, taste, &c.
which serve to distinguish the bile from the other
inquiline humours belonging to the system; and
from the same source must we also derive the other
remarkable properties of this fluid, which shall be
mentioned hereafter.
The bile is not of such a nature as to possess,
like soap, an equal affinity to oil and water, and
thus serve to mix and intimately combine these
two elements together. The contrary opinion
(which was erroneously entertained on this subject
by Boerhaave, and afterwards by Schroder) was
formerly invalidated and refuted by certain re-
markable experiments of my own (since confirmed
[Seite 43] and further increased by other writers), and is
now entirely repudiated by the greater number of
physiologists. On the other hand, if bile be ap-
plied to the two foregoing elements, i.e. oil and
water, when in a state of intimate mixture and
combination, it produces an evident disunion and
separation of them from each other. This fluid
possesses indeed no alkaline properties, but is, not-
withstanding, equally unfriendly to the existence
of acid acrimony, to fermentation, and to putre-
faction.
By considering with due attention the foregoing
observations, we may easily ascertain the true, the
important, and the diversified uses of the bile, in
the process of chylification.
For in the first place, from that equable and
uniform chymous pulp which the stomach has dis-
charged into the duodenum, which the pancreas
has diluted by an effusion of its own juice, and
which moves spontaneously onward to the cavity
of the small intestines, it gradually precipitates the
faeces, and thus separates from them that cream-
like fluid denominated chyle.
The bile itself suffers, at the same time, a divi-
sion into two parts, the one aqueous, the other
phlogistic. The latter part adheres to the faeces,
tinges them, and is afterwards discharged, along
with them, out of the body; whereas the former
appears to be mixed with the chyle, and re-con-
ducted back to the mass of blood.
Thus the abundant phlogiston, now become
troublesome and noxious to the blood, is first di-
rected to the liver, where it is rendered subservient
to the formation of a singular and very important
humour: After this humour has fully answered
the end of its destination, its superfluous, or rather
noxious part is included among the excrements,
and finally eliminated from the system.
A further use of the bile is, to evolve and ex-
terminate from the alimentary canal, the fixed air,
which had been hitherto confined among the chy-
mous mass: it appears also to act on, and aid, the
intestinal tube, by means of its stimulus, thus ex-
citing it to perform its peristaltic motion with
greater vigour and energy.
I silently pretermit a variety of other uses, com-
monly attributed to the bile, which appear to me
to rest on more doubtful and equivocal evidence,
[Seite 45] such, for instance, as its power of regurgitating
into the stomach when empty, and thus exciting
appetite, a phenomenon that, in my opinion, can
very seldom occur in a well formed and healthy
human subject.
The spleen is very intimately connect-
ed with the liver, not only by an intercourse of
vessels, but also by the affinity and subserviency of
its function: it is situated in the left hypochon-
driac region, opposite to the liver; its figure is
oblong, generally, indeed, accommodated to the
situation of the neighbouring viscera with which it
lies in contact: it is subject however, to multiplex
varieties with regard to form, number, and other
species of lusi naturae, or preternatural pheno-
mena.
Its colour is livid, its texture altogether singu-
lar, being soft, friable, easily lacerated, and there-
[Seite 46] fore securely protected by two membranous cover-
ings, the internal of which belongs properly to
the spleen itself, while the external appears to be
derived from the omentum.
The situation and size of the spleen are now and
then, no less than its figure, subject to striking
and singular variations, arising in a great measure
from the different states of the stomach, with re-
spect to fulness and depletion: thus, for example,
when the stomach is empty, and hangs in a loose
and depending position, the spleen is distended
with blood; but when the former viscus becomes
turgid again, the latter is emulged, and conse-
quently diminished in bulk by the pressure to
which it is subjected.
The spleen is also agitated by another perpetual,
though gentle and uniform motion, in consequence
of respiration, being subjected to the immediate
action of a primary instrument of that function,
namely, the diaphragm.
The texture of the spleen, physiologists former-
ly supposed to be cellular, and uniformly compared
it to the corpora cavernosa of the penis: this opi-
nion, however, is evidently founded in error, and
[Seite 47] has been very satisfactorily refuted by a more ac-
curate examination of the human spleen. For,
from such examination we learn, that almost the
whole volume of this viscus is composed of blood
vessels, extremely large in proportion to its size;
so that it is supplied with a greater profusion of
blood, than any other part belonging to the body
of man.
The splenic artery, conspicuous (agreeably to
the experiments of Wintringham) on account of
the astonishing fineness and strength of its coats,
is divided into an infinitude of minute ramifica-
tions, which constitute finally, by their evanescent
extremities, very small pulpy pencils: these pencils
afford origin, again, to fine filiform veins, that
constitute by their gradual confluence, large and
lax trunks highly capable of dilatation.
This vast congeries of blood vessels, is, how-
ever, knit together and supported by a small quan-
tity of cellular parenchyma, from whence the ab-
sorbent vessels arise, the trunks of which run on
the plain or flat side of the spleen, between the
two membranous coverings, of which we have al-
ready spoken.
This texture of the spleen, so very lax and high-
ly capable of admitting blood, corresponds admi-
rably with what we formerly said respecting the
sanguineous distension of this viscus (§ 395): and
we may further observe, that the phenomena of
the congestion, and tardy progressive motion of this
crimson fluid in the spleen, considered in conjunc-
tion with the nature of the surrounding and conti-
guous viscera, tend not a little to illustrate the pe-
culiar state and condition of the splenic blood,
which of themselves appear to shed considerable
light on the function of this mysterious viscus, a
subject of such repeated controversies among phy-
siologists.
The blood contained in the veins of the spleen
is very fluid, dissolved, coagulated with the utmost
difficulty, and admits of but a slight and partial
separation of the serum from the crassamentum;
its colour is also livid and obscure, as in the foe-
tus; all which phenomena appear evidently to
combine in ascertaining and even demonstrating
the presence of an abundant quantity of the phlo-
gistic element. That this element is, however,
unequivocally present in large quantities, I further
ascertained to my entire satisfaction, by the follow-
ing simple and conclusive experiment: to the ac-
[Seite 49] tion of pure dephlogisticated air, I exposed recent
sections and slices of the spleen of a human subject;
no sooner were these pieces brought in contact
with this vital fluid, than they were overspread
with a very florid and beautiful crimson blush,
while the air itself, thus despoiled of its native
fire, was on the other hand, contaminated by the
splenic phlogiston.
When we contemplate the foregoing circum-
stances collectively, and consider in the last place,
that the spleen is the only viscus of a similar nature
wholly unfurnished with any vestige of an excre-
tory duct, save those vessels which we have alrea-
dy said run to the liver, we are obliged from the
force of concurring testimony to conclude, that
the sole office of the organ now under considera-
tion, is to act in subserviency to the function of the
liver, and contribute towards the formation of
bile by the co-operation of its phlogistic parts.
This opinion is still farther substantiated by a
very curious and useful observation, made on such
individuals of the animal kingdom, as have been
deprived of the spleen by excision. It appears
that in animals subjected to this operation (which,
however singular and seemingly barbarous, has
[Seite 50] been, notwithstanding, very frequently performed
from remote periods of time) the cystic bile has
been uniformly afterwards found to be pale, weak-
ly impregnated with phlogiston, and disposed to a
grume-like coagulation of its lymphatic portion.
The omentum gastrocolium, or omentum
magnum, (so called to distinguish it from the par-
vum or hepaticogastricum), is indeed a very singu-
lar production of the peritoneum, originating im-
mediately from the external coat of the stomach.
For notwithstanding the continuations of the
peritoneum, in the abdominal cavity, be almost innu-
merable, and although all the parts contained in
this cavity, whether viewed collectively or indivi-
dually, be so uniformly invested by it, that, on
opening the abdomen, it is impossible to discover
a single viscus which this membrane does not em-
brace, yet the modes in which it furnishes this
[Seite 51] covering to the several viscera, are so diversified,
as to merit a division into different classes.
Thus, for example, the abdominal cavity con-
tains certain parts, over which the peritoneum is
only spread in such a partial and simple manner,
as to invert; but one of their surfaces; this obser-
vation may be applied particularly to the kidneys,
the intestinum rectum, the vesica urinaria, and in
some measure also, to the pancreas and gall-
bladder.
There are also other viscera, which, notwith-
standing their attachment and adhesion to the sur-
rounding parietes of the abdomen, yet project also
to a considerable distance into the abdominal ca-
vity itself, and derive from the peritoneum a co-
vering, which inverts, by far, the greater part of
their external surfaces: of this description are the
liver, the spleen, and even the stomach and female
uterus, to which we may add, finally, the testes
of a male foetus, previously to their descent into
the scrotum.
Considerably different again, (in point of peri-
toneal covering), from both the foregoing classes
of viscera, is the whole of the intestinal tube, ex-
cept that portion which is denominated intestinum
rectum. This tube passes through the adominal
[Seite 52] cavity in such a manner, as to carry along with it,
two remarkably broad processes of the peritoneum,
namely the mesentery and mesocolon, to which it
adheres in a state of suspension: under the same
class with the two preceding processes, may we
also arrange those singular peritoneal productions,
denominated the broad ligaments of the uterus.
But finally, the most extensive of all is that pe-
culiar continuation of the peritoneum called the
omentum. This production is a large empty sac
of a very delicate texture, that hangs in a depend-
ing position from the great curvature of the sto-
mach; it is spread over the region of the small in-
testines in particular, nicely adapts itself to their
irregular convexities, and dips down, in some
measure, into their numerous interstices.
Besides the blood vessels by which the omen-
tum is painted, it is also marked by numerous
striae or broad lines of adipose substance, which
meet, intersect, and thus form a variety of reticu-
lar intertextures, from whence the membrane has
received the name vernaculum. In persons dis-
posed to obesity this adipose substance encreases
now and then to such a size, as to become not only
troublesome but even dangerous: it is also this
[Seite 53] adipose portion that affords origin to that oily
halitus by which the omentum is constantly sur-
rounded and moistened.
It has been the opinion of certain celebrated
characters, and a further attempt was made by
the illustrious Haller to prove, that the fat con-
tained in the omentum is destined to be taken up
by absorption and conveyed to the liver, for the
purpose of supplying the bile with its oily portion,
&c. With respect to the truth of this opinion,
however, I must still be permitted to entertain and
express a serious doubt, having never yet been
convinced that sound, uncontaminated, bile con-
tains any oil; nor have I ever been able to disco-
ver any orifices subservient to such an absorption,
not even in frogs themselves, where Malpighi al-
leged, and even attempted to prove, their exis-
tence; much less in that part which is the subject
of our present confederation, namely, the omentum
of man.
What appears, from the nature and situation of
the part, as well as from the concurring belief of
all physiologists of the present day, to be a much
more unequivocal use of the omentum, is, to lu-
bricate the intestines, and by that means aid and
[Seite 54] facilitate their perpetual motion. The same ap-
pear also to be the use and destination of certain
similar, but small, adipose bursae, by which the
colon and rectum are invested.
The omentum also further serves to prevent the
occurrence of an adhesion between the intestines
and peritoneum, by which the whole office of the
primae viae would be subverted.
That this adipose curtain is destined to serve as
a defence against cold, (though an opinion very
generally received), appears, notwithstanding, to
rest on evidence of a more questionable nature:
the omentum of a man in perfect health, which
ought by no means to be burthened with an accu-
mulation of fat, is indeed, but very illy calculated
to answer such an intention.
When we consider, in the mean time, the sin-
gular structure of the two omenta, more especially
of that denominated omentum parvum or gastrohe-
paticum, it appears sufficiently probable, that be-
sides the uses already enumerated, the latter is still
destined for another, of, perhaps, even supreme
importance, which is as yet unknown to us, and
which future researches in comparative anatomy
will be alone able to develope.
The intestinal tube itself (before which
the omentum is spread, and into which we have
already seen the chyme conveyed, in order to be
further elaborated and sufficiently fitted for the
separation of chyle), is divided into two leading
portions, namely, the small and great; of the
functions of which we will now treat separately
and in order.
The small portion of intestines is again subdi-
vided into three parts, namely, the duodenum, je-
junum, and ileum.
The duodenum derives its name from the cir-
cumstance of its length.
The jejunum from that of its general habit, be-
cause, in a recent corpse, it appears collapsed and
empty as it were, even although it contain at the
same time a quantity of pulpy chyme. In the
third division, called ileum, the chyme deposits its
faeces, and suffers an evolution of its air, which
[Seite 56] had been hitherto fixed, so that this last of the
small intestines, being at the same time the longest,
and deriving its name from its circumvolutions,
appears more turgid, somewhat inflated, and mark-
ed here and there with small bubble-like emi-
nences, after the manner of the large portion of
this tube.
The coats of the small intestines are perfectly
similar to those composing the stomach, of which
we have already spoken (§ 359.)
The external is a production of the mesentery.
The muscular coat consists of two orders of
fibres, to wit, longitudinal, which are interrupted
in their course, and run rather externally, especi-
ally on that side of the intestine that looks in a
contrary direction from the mesentery; and more
internal, annular, or falciform fibres, which are
calculated to contract or narrow the diameter of
the tube; whereas the former are intended to di-
minish its longitudinal extent. On both the pre-
ceding orders of fibres depends that exquisitely
energetic and pertinacious irritability of the intes-
tines, of which we have spoken on a former occa-
sion (§ 306.)
The nervous coat consists of compacted cellular
membrane; and may, by a very simple mode of
treatment, especially by blowing into it, be again
reduced to a spongy, foam-like tissue: throughout
this coat a variety of blood-vessels, detached from
the mesenteric, are distributed in the form of ar-
borets or branching shrubs, of inimitable elegance
and beauty. As in the stomach, so likewise in the
intestines, the nervous coat is the principal seat of
tenacity and strength.
Finally, the internal coat (which merits more
unequivocally, in the small intestines, than in any
other part of the alimentary canal, the name vil-
lous), is continued here and there, in conjunction
with the internal surface of the preceding mem-
brane, into wave-like productions and rugous
folds, that in the intestines, when inflated and
dried, exhibit a falciform appearance, and are de-
nominated valvulae Kerkringii.
Of the villi themselves, an immense number
overspread, in the closest order, the whole inter-
nal surface of the small intestines: their subtle and
exquisitely elegant vascular structure, was first dis-
covered and demonstrated by the labours of the
indefatigable Leiberkuhn. While the intestines
are destitute of chyle, the villi may be compared
[Seite 58] in some measure to small purses hanging in a loose
and flaccid position, and consisting internally of a
soft spongy texture; but when they become tur-
gid, in consequence of the absorption of this
milky fluid from the intestinal canal, their figure
undergoes such a striking change, as to bear no
small resemblance to the phallus esculentus*.
Those villi are surrounded, at their bases, by
an infinitude of small glandular follicles, which are
lodged principally in the nervous coat, and com-
municate by very minute orifices with the intesti-
nal cavity, into which they discharge a mucus that
serves to line and lubricate the whole internal sur-
face of that tube.
These minute glands are commonly supposed to
consist of three orders. First, the Brunnerian or
larger glands, which are separate from each other,
and situated principally on that part of the duode-
num, which lies next to the pylorus.
Secondly, the Peyerian, which are considerably
smaller, planted in clusters, and lodged, in parti-
cular, on the other extremity of the small intes-
[Seite 59] tines, which looks towards, and is contiguous to,
the valve of the colon.
And, lastly, the glands of Leiberkuhn, the most
minute of all, of which about eight are said to be-
long to each villus.
It ought to be observed, however, that this di-
vision of the sources of mucus appears to rest on
very equivocal evidence. For if I be not greatly
deceived, both the Brunnerian and Peyerian
glands, as commonly exhibited in plates, are the
result of a vitiated and diseased state of the intesti-
nal tube. I am induced to entertain this opinion
from having never been able to discover, in the
sound small intestines of subjects carefully exami-
ned in different periods of life, the smallest vestige
of such fungous papillae, perforated with orifices;
whereas, on the other hand, I have frequently
seen, in cases of aphtha, almost the whole intesti-
nal canal planted with countless numbers of them,
partly standing alone, and partly arranged in
crouded clusters. From considering the foregoing
circumstances, I feel a confidence in concluding,
that none can be accounted true muciferous
glands, except those extremely minute miliary bo-
dies, which, on gently separating the villous lining,
may be readily detected on its averted surface, but
[Seite 60] cannot, without great difficulty, be distinguished
on the side next to the eye.
It has been incontrovertibly established, not
only from that well known experiment first insti-
tuted (if I mistake not) by Pechlin, but also from
several others, that as the stomach, so in like
manner the cavity of the small intestines, is sup-
plied with a constant influx of a liquid, denomi-
nated, from the place into which it is discharged,
intestinal juice. It appears probable that this fluid
is similar in its nature to the gastric liquor, al-
though a more accurate investigation of it is, cer-
tainly as yet, a desideratum in physiology: nei-
ther can I venture to say any thing decisive re-
specting the quantity of this liquid secreted: I am,
however, fully of opinion, that Haller has been
too profuse in his estimate, where he alleges,
that this secretion amounts to eight pounds in the
space of twenty-four hours.
Further, it is also common to the intestines with
the stomach, to be agitated by a similar, but far
more lively and vigorous peristaltic motion, which,
in particular, while the chymous pulp is advancing,
onward, throws the same into gentle commotion,
[Seite 61] by a wavy and progressive constriction, and thus
propels it forward from the duodenum towards
the great intestines. For although we cannot ab-
solutely deny the phenomenon of an anti-peristal-
tic commotion, in consequence of which the intes-
tines are subjected to a retrograde action, it must,
notwithstanding, be acknowledged, that this, in a
healthy subject, is much feebler than the former,
that it occurs more rarely, and possesses a more
precarious and short-lived existence.
In consequence of the co-operation of those
energetic causes, hitherto enumerated (viz. both
the principles of motion, of which we have just
spoken, and likewise the solvent and alterative
powers of the inquiline humours that are every
where blended in abundance with the chyme), the
following remarkable changes are produced in this
heterogeneous mass: – in the jejunum it exhibits
the appearance of a more liquid pulp, possessing a
colour somewhat grey, and an odour slightly acid:
after its entrance into the ileum it begins to sepa-
rate into two portions; these are, first, the faeces,
marked by a pale yellow colour, inclining more
or less towards a brown, and possessing a fetid
odour; and secondly, a white milk-like fluid, de-
nominated true chyle, which floats on the surface
of the faeces, and is separated from them by the
[Seite 62] action of the hepatic liquor or bile. This chy-
mous emulsion, designated by the name of chyle,
is destined to be received by absorption into the
lacteal vessels, through which mazy tubes we will
accompany it farther in the following section; and
shall, in the mean time, close the present, by tra-
cing, in as brief and intelligible a manner as pos-
sible, the route pursued by the residuary faeces.
These, therefore, after having become more and
more inspissated, in consequence of a tedious course
through the ileum, are obliged at length to pass
the valve of the colon, and thus enter the tract of
the great intestines; for which purpose the neigh-
bouring extremity of the ileum is furnished, and
lubricated internally, by a more copious quantity
of mucus, destined to destroy the friction of the
faces, and consequently facilitate their transition
through the foregoing valve.
The valve of the colon (denominated very justly
in honour of its real and illustrious discoverer,
valvula Fallopii), is a short continuation or process
of the ileum projecting into the cavity of the great
intestinal portion, by which it is surrounded and
closely embraced: the more exterior labia of this
process are so constituted, by means of a more
[Seite 63] prominent or extensive ruga of the great intestine,
as to consist not only of its internal and nervous
coats (as is the case with the greater number of
such plicae), but to contain also in its composition
some fibres from the muscular coat. Hence the
function of this valve appears to be twofold, to
prevent the premature passage of the faeces from
the small into the great intestines, and also to ob-
struct their regurgitation from the latter into the
former.
The great intestinal portion, which in like man-
ner with the small, is also divided into three sec-
tions, begins from the caecum (to which is append-
ed the vermiform process, a part indeed of equivo-
cal use in the economy of an adult subject), and
constitutes collectively a canal so capacious, as to
admit the inspissated faeces to be gradually collected
and retained in its cavity, till a convenient oppor-
tunity for their evacuation.
As the great is superior to the small portion of
the intestines in diameter, so it likewise exceeds it
in the thickness and strength of its coats. The
muscular coat, in particular, possesses this peculia-
rity, that its longitudinal fibres (if we except the
lower part of the rectum) are collected into three
[Seite 64] fasciculi or bundles, called ligamenta coli; and the
colon itself is thus divided into distinct segments of
a vesicular or cystiform appearance. The internal
coat in the great, is not of such a beautiful and
elegantly floccose appearance as in the small in-
testines, but possesses a nearer resemblance to that
which inverts the cavity of the stomach.
The peristaltic motion appears to be less vivid
and active in the great, than in the small intestines.
On the other hand, the abdominal pressure is con-
siderably greater on the former than on the latter,
in as much as the whole colon is subjected to its
immediate action and influence.
The inspissated and hardened faeces contained in
the large intestines, are protruded slowly onward,
till having at length reached the restum, they ex-
cite, by their stimulus on the internal surface of
that tube, a propensity to an evacuation. For the
purpose of facilitating this evacuation, ample and
wise provision is made, partly by a defect or inter-
ruption in the transverse rugae, but more especi-
ally by a profuse quantity of mucus, that lubri-
cates the internal surface of the rectum near to its
extremity.
The evacuation of the faeces is, however, prin-
cipally accomplished by a downward direction of
the abdominal pressure, overcoming the resistance
of the coccyx and both the sphincters, the interior
of which is a very singular fascisculus or bundle
of annular fibres, but the exterior, a genuine cuta-
neous muscle: these ends being quite completed,
there succeeds an entire remission of the abdominal
effort, the intestine is retraced by the levator ani
in particular, and finally closed again by the con-
traction of the sphincters.
From observations delivered in a for-
mer section it is sufficiently evident, that the chyle,
which we left in the intestinum ileum, completely
disengaged from its faeces, is a compound of seve-
ral different humours. Although it be almost li-
terally impossible to calculate, with accuracy and
definitude, the precise quantity of inquiline hu-
mours, such as saliva, gastric juice, pancreatic juice,
intestinal juice, bile, &c. that is mixed and blended
[Seite 66] with the chyme, it appears, notwithstanding, a
matter of the highest credibility, that these several
humours, taken collectively, very far exceed, in
quantity, the other constituent part of the chyle,
which is derived immediately from alimentary sub-
stances, recently taken as nutriment. Hence we
may derive a solution of that problem in physio-
logy, by what means alimentary matters, though
of the most different and even opposite kinds, may,
notwithstanding, be converted into the same assimi-
lized, homogeneous, and milk-like chyle, equally
adapted to the nature, and calculated to serve as
the nutriment, of animals?
The channels through which the chyle must
flow, in its passage from the intestines to the mass
of blood, (the reservoir destined for its ultimate re-
ception), constitute a part of the absorbent system,
which we have hitherto mentioned only occasion-
ally, and in a very cursory manner, but will now
assume as the professed object of our present at-
tention. This system is divided generally into
four parts, viz. lacteal veins; lymphatic veins;
conglobate glands; and finally, the thoracic duct,
each of which shall constitute a subject of exclu-
sive consideration.
With respect to the nascent origin of the lac-
teals from the intestines, there exists scarcely a
doubt, but that this is constituted by the innume-
rable villi of the internal intestinal coat, of which
we have already spoken. It is, however, still a
matter of controversy, whether the lacteals origi-
nate immediately from those villi themselves, or
only preserve a more distant intercourse and com-
munication with them, by means of interjacent
cellular substance. As far as my information has
extended, no one has hitherto been able, more
than myself, to trace the evanescent radicles of the
lacteal vessels to the villi themselves, with such
clearness and definitude, as to discover an imme-
diate and unequivocal connection between the
parts; on the other hand, the lacteals appear here
and there;, throughout the coats of the intestines,
to form trunks of considerable size, immediately
after their orgin, and, (if a conjecture be allow-
able), to absorb from the cellular substance of the
adjacent parts, that chyle which had been origi-
nally taken up from the cavity of the intestines by
means of the villi themselves. This phenomenon
I think I have frequently observed, in young pup-
pies, into which I had poured, according to the
celebrated experiment of Lister, a solution of In-
dian blue, one or two hours before subjecting
them to the operation of live-dissection.
Those trunks, of which we have just spoken,
frequently run the distance of several inches, and
sometimes even wind about in angling or mean-
der-like directions, immediately under the external
coat of the intestine, previously to their entrance
into the mesentery.
During their passage through the mesentery,
these trunks make frequent entrances into small
mesenteric glands, which may be divided into two
different series or orders. Those of the first order
are situated in the vicinity of the intestinal tube,
and resemble, in their appearance, small beans ly-
ing separate from each other. The glands of the
other order, lie nearer to the receptacle of the
chyle, are superior in magnitude, and planted in
collective clusters.
Both the foregoing kinds of glands appear to
be in reality nothing else, than round compacted
convolutions of the lacteal vessels themselves, co-
vered and interspersed with an infinitude of minute
blood-vessels: their destination appears to be, to
retard the progressive motion of the chyle, in or-
der, perhaps, that, by such delay, it may be more
fully and perfectly animalised and matured, previ-
[Seite 69] ously to its entrance into the thoracic duct, and
subsequent admixture with the circulating volume
of the blood.
It has been proposed as a physiological question,
whether or not the large, possess also lacteal veins,
in common with the small intestines? The affirma-
tive of this has been zealously advocated, and its
defence attempted by arguments drawn from the
influence and efficacy of specific enemas, of ene-
mas composed of nutrimental substances, of ine-
briating substances, &c. and also from the follow-
ing well known circumstance, viz. that the longer
inspissated faeces are retained in the large portion
of the alimentary canal, the more indurated and
insucculent they are uniformly found. But al-
though these arguments do not satisfactorily de-
monstrate that any genuine chyle is absorbed from
the faeces after their transition over the valve of
Fallopius, they furnish, notwithstanding, additional
evidence in confirmation of that, which has indeed
been long since established on the testimony of
the sense of vision itself, namely, that the great in-
testines abound with a sufficiently plentiful appa-
ratus of lymphatic veins, perfectly similar to the
lacteals both in their structure and functions: in
testimony of this entire similarity, it may be proper
to observe, that when the intestines are destitute
[Seite 70] of chyle, the lacteals of the mesentery are then
engaged in the absorption of lymph.
Another question, more important and difficult
of solution than the former, is, whether or not
the whole of the chyle, absorbed from the cavity
of the small intestines, be conveyed to the blood
through the same public, and royal route, as it is
termed, or whether there do not exist certain se-
cret channels, through which it may glide surrep-
titiously onward, to mingle its streamlets with the
general current of circulating blood?
It must indeed, be confessed, that most of the
arguments, by which physiologists have endea-
voured to prove a private absorption and convey-
ance of chyle through the sanguiferous veins, do
not appear to rest on a very solid foundation:
thus the assertion of Ruysch, that on the approach
of old age the mesenteric glands become so indu-
rated and constricted, as to be rendered unfit for
performing their functions, has been long since re-
futed, and it has, on the other hand, been satis-
factorily demonstrated that, different affections of
these glands, such as swellings, &c. very errone-
ously pass under the common name of obstructions,
while, at the same time, their vessels remain in a
state sufficiently pervious to afford a very easy en-
[Seite 71] trance and transition to injections of quick silver.
That well known phenomenon, from which it is
ascertained, that tepid water, thrown into the inert
mesenteric veins of a dead subject, transudes into
the cavity of the intestines, appears to contribute
but very little towards the satisfactory elucidation
of any function of the human body while in a
living state; much less can we repose confidence
in the evidence derived from that bicrural and two
branched tube of copper, which was invented by
Lieberkuhn, for the purpose of confirming the
same opinion. As to the assertion, that chyle has
been unequivocally detected in the red veins of
the mesentery, it appears to me to stand in need
of farther evidence for its unquestionable confir-
mation; on the whole, I have never yet been
convinced, that those veins convey any thing else
than blood very highly charged with phlogiston,
destined for the secretion of bile.
Finally, the ultimate trunks of the lacteal veins,
(with certain other tubes very similar in appear-
ance and function, which are formed by the con-
fluence of a great number of minute lymphatic ves-
sels), unite and constitute by their junction, the
receptacle or cistern of the chyle, which is a name
given by physiologists to the inferior and larger
[Seite 72] portion of the thoracic duct, called also the duct of
Pecquet.
This duct is a membranous canal, of a delicate
appearance and texture, yet sufficiently robust and
strong, more or less circuitous in its course, and
not unfrequently subject to very striking diversities
with regard to the direction in which it runs, and
the divisions it occasionally undergoes: it is equal-
ly destitute of muscular fibres and nerves, is fur-
nished here and there with small valves, and, after
having passed over the left subclavian vein, is again
reflected towards, and finally inserted into, the
same, and, at the very point of insertion, has its
entrance guarded by a valve of a peculiar struc-
ture.
The powers which produce and continue the
onward motion of the chyle, both in the lacteal
veins, and through the thoracic duct, are to be
attributed, indeed, principally to the contractility
of these vessels themselves, but, in part also, to
the valves with which they are furnished, to a
propulsive vis a tergo, and to the uninterrupted
pulsation of neighbouring arteries.
It appears probable, that the principal detona-
tion of the valve, which is fixed, as has been al-
ready observed, in the entrance of the chyliferous
duct into the subclavian vein, is not so much to
obstruct the lateral passage of blood into this duct,
as to regulate the necessary discharge of chyle in-
to the vein, and prevent its admission in any other
manner than by a slow and gradual stillicidium.
By this means, adequate provision is made
against the simultaneous entrance of too large a
quantity of recent chyle, into the mass of blood.
Such an excessive influx of this crude fluid would
necessarily stimulate the parities of the heart so ex-
ertions too violent and laborious, and would be
blended and assimilated by the same, with the ut-
most difficulty, and in an imperfect manner; that
this would be the result, we judge from the nature
of recent chyle, which is a compound of hetero-
geneous elements, derived not only from the pri-
mae viae, by means of the lacteal, but also from
all the other parts of the body, through the ave-
nues of the lymphatic vessels.
The lymphatic veins themselves, which consti-
tute a third part of the absorbent system, and bear
[Seite 74] a very close resemblance to the lacteals, both in
structure and in function, are so considerable, in
point of extension, as to pervade, perhaps, every
part of the human body; but originate, in parti-
cular, from the common external integuments,
from the pleura, the peritoneum, and viscera,
contained in the thorax and abdomen.
The manner in which they arise, is similar to
the origin of the lacteals from the intestines, of
which we have already spoken. Thus each radi-
cle of each lymphatic vessel, is destined to absorb
from a neighbouring portion of cellular membrane,
(as from a territory of its own), the moisture it
contains, and propel it onward to the general cis-
tern of the chyle.
These lymphatic vessels are furnished in their
course, sometimes more frequently, sometimes
more rarely, with valves situated in bigae or pairs.
By far the greater part of them enter conglobate
glands; those in the vicinity of each other fre-
quently anastomose; and such of them as over-
spread the surface of certain viscera, as that of the
lungs, the liver, &c. form exquisitely elegant reti-
cular expansions.
To pass silently over certain other aids, suffici-
ently evident from former observations, the func-
tion of the lymphatics is greatly promoted by their
remarkable contractility, and the strength of their
delicate coats, which is sufficient, in processes for
anatomical preparations, to resist the pressure from
a ponderous column of quick silver: this function
is also further aided, especially in the joints, by
muscular motion, in consequence of which, the
lymphatics being compressed and closely embraced
on all sides, have their tone remarkably aug-
mented.
With respect to the terminations of the lym-
phatics, various controversies have lately existed
among physiological writers. Thus, while some
contend, that all those vessels unite in the thoracic
duct, (in like manner as the sanguiferous veins
unite in the venae cavae), others, on the contrary,
exempt from this general confluence, at least the
lymphatics of the right arm, and right side of the
neck, which they allege are not inserted into the
same duct, but into the right subclavian vein:
others again assert that in the conglobate glands,
the lymphatics communicate immediately with san-
guiferous veins; and lastly, others maintain (not
indeed without an appearance of probability) that
[Seite 76] certain lymphatic vessels*, actually exist, which
form a direct and free communication between the
intestinal tube and uropoietic organs.
Seeing therefore, the lymphatic vessels are
extended far and wide throughout almost the
whole system, and, especially, in as much as an
immense profusion of them originate on the cuta-
neous surface of the body, and may consequently
absorb such fluids as are applied from without, it
is sufficiently evident, that the lymph, when re-
cently absorbed, must be, indeed, a liquid compo-
sition extremely heterogeneous and diversified as
[Seite 77] to its nature and elementary parts: this diversity
is fully ascertained and established, by a more
careful and accurate examination of dead subjects,
where, for instance, the liquid contained in the
absorbents of the liver and spleen, appears to be
evidently different from that discovered in those
which run to the uterus.
Of the conglobate glands, (which constitute the
last branch of the lymphatic system), the prin-
cipal use and destination appear to be, to assimi-
late to the animal nature this subtle and hetero-
geneous fluid, especially that portion of it which
is absorbed by the lymphatics of the skin: this
assimilation they accomplish by retarding and in
some measure obstructing the motion of the lymph,
and perhaps also by the addition of a new fluid,
derived from the minute arteries, with which they
very plentifully abound. Hence a wise and ade-
quate provision is made, to prevent the humours,
while in too crude a state, from effecting a prema-
ture mixture with the blood, and thus the heart
is guarded in perfect security from their noxious
impressions.
With respect to those other glands of the same
nature, which are minutely dispread throughout
[Seite 78] by far the greater part of the system, and planted
here and there in collected clusters, as in the
groin, beneath the axilla, &c. they bear, in every
respect, the most perfect resemblance to the me-
senteric glands, of which we have already spoken;
like them they are composed, in a great measure,
of the mazy convolutions of absorbent veins; like
them they are furnished with a vast profusion of
minute blood vessels; and finally, they are subject
to be readily invaded by the same diseases that
attack the glands of the mesentery.
It is scarcely necessary to observe, that
by the term sanguification, we mean the assimila-
tion of chyle to blood, and the constant and uni-
form restitution made by means of the former, for
the equally constant and uniform loss which is sus-
tained by the latter.
For on this principle depends that division of all
the humours of our body, into the three classes
[Seite 79] (§ 4. 5.) crude, sanguineous, and secreted; viz.
that the middle class embrace the whole circula-
ting volume of blood, from which the different se-
creted humours are derived in constant streamlets,
and to which the countless channels of the absor-
bent system convey their chyle, and the infinitude
of lymphatic tubes return their absorbed fluids in
currents equally constant and uniform.
Seeing the blood is an animal humour of so very
singular and exclusive a kind, as to be wholly dis-
similar to every other fluid yet discovered in any
department of nature, it is a proposition sufficiently
self-evident, that there must be a variety of assist-
ant powers which contribute, by their joint co-
operation, to incorporate and assimilize with the
blood, the heterogeneous and adventitious hu-
mours, which it is constantly deriving from the
thoracic duct.
The process of sanguification we may consider,
then, as first commencing under the action and
influence of those mazy circumvolutions (frequent-
ly spoken of already), which both the lacteal and
lymphatic veins exhibit occasionally in their courses
(more especially in the mesenteric and other con-
[Seite 80] globate glands), and which are, at the same time,
furnished with considerable quantities of what may
be called animal and inquiline contagion.
It is necessary further to consider, that a great
part of the lymph, which enters the subclavian
vein (after having first effected a mixture with the
intestinal chyle in the thoracic duct), is derived
from the interior recesses of the viscera and other
soft parts of the body, and was formerly secreted
from the blood itself; from whence it necessarily
follows, that such portion of the lymphatic fluid
must doubtless possess, already, the animal nature
entire, and be very readily miscible with the mass
of blood to which it is returned.
To these we may add another circumstance, of
which we spoke on a former occasion, namely,
the slow and stillicidious transition of the chyle into
its reservoir, the blood – that fluid not being ad-
mitted to pass through the ultimate valve of the
thoracic duct into the subclavian vein, in any
other manner than by drops, in order that those
minute portions may, by this means, be more inti-
mately mixed and incorporated with the circu-
lating blood.
The internal structure of the heart itself appears
also to contribute, not a little, towards the im-
portant process of sanguification. Thus, by means
of those astonishing muscular papillae, with which
the ventricles of the heart are plentifully fur-
nished, the blood and chyle (having recently met
together), are thoroughly agitated, and brought
into a state of more intimate combination.
That the lungs, receiving the blood, recently
impregnated with chyle, perform, by the function
of respiration, an important part in the further
assimilation of this crude fluid, will appear suffici-
ently evident to any one who considers the asto-
nishing vascular structure of these viscera (§ 136.)
in conjunction with the equable alternate motion
to which they are perpetually subjected, during
the continuance of human life.
The remaining part of the process of sanguifica-
tion is finally completed by the more extensive
circuitous journey of the blood throughout the
whole body, and by those powers which con-
tribute towards the continuance of the same,
more especially muscular motion, &c.
But although potent provision be made, by
such powerful and diversified apparatus, for blend-
ing and intimately incorporating the chyle with
the blood, it appears, notwithstanding, that there
exists a certain similarity between the constituent
parts of those two fluids. It is very commonly
asserted, that a great many hours must elapse be-
fore the chyle can be completely diverted of its
own milky colour, and perfectly assimilated to that
of the crimson fluid into which it is destined to be
converted: in testimony of the truth of this asser-
tion, medical philosophers usually adduce (besides
other arguments) the following singular patholo-
gical phenomenon, namely, that several hours after
the close of digestion, genuine chyle has been fre-
quently observed to flow from an orifice made in
a vein of the human body: this phenomenon I
have indeed had an opportunity of observing my-
self; but it was at the same time extremely evi-
dent, that the blood was then highly charged with
phlogiston (a condition of this fluid very un-
friendly to the regular assimilation of chyle), so
that from hence scarcely any inference can be
drawn relative to the healthy state of the system,
which is alone the exclusive subject of the science
of physiology.
Besides that function (which we at-
tributed to the blood in a former section) of dis-
tributing the element of fire throughout the whole
body, and in its place wasting that of phlogiston
back to the lungs, two of its primary and leading
offices appear to be, to convey to the body nou-
rishment, and to the secretory organs the matter
of those peculiar fluids which they are severally
destined to extract. Of this twofold function we
will next treat; and first of the function of nu-
trition.
Nutrition is the supreme privilege of nature.
It is a common and leading prerogative of all or-
ganized bodies, whether animal or vegetable, by
which they are instantly discovered, on first view,
to surpass, in an immeasureable degree, all ma-
chines and automatons constructed by human ar-
tifice: because on none of these latter has any
artist ever been able to confer a power (I will not
say of actual growth, of progressing toward matu-
rity, and of acquiring gradually higher and higher
[Seite 84] degrees of perfection), but not even of preserving
themselves in a state of stationary existence by their
own inherent powers, nor of repairing the gradual
losses to which they are subjected by attrition, by
incidental casualties, &c.
Nutrition is that faculty of our bodies, on which
all the sublime and astonishing functions of our na-
ture depend. By means of this faculty we increase
in magnitude from the earliest dawnings of our
existence, we advance through the expanding
period of youth, and finally arrive at our acme,
or point of complete maturity. It is also through
the instrumentality of this same faculty that a com-
petent remedy is applied, and sufficient restitution
made, for that uniform waste and loss of the body,
by which (while in a living state) it destroys and
in some measure consumes itself, by its own neces-
sary action.
With respect to the nature and mode of this
wasting or loss, various controversies have existed
among physiologists. The more immediate point
of disputation has been, whether such waste occurs
in the solid parts of our bodies, or whether it be
not more probable, that those parts, when once
formed and completed, remain stationary, without
[Seite 85] being subject either to vitiation or change? which
latter is indeed an opinion embraced and taught
by several characters of the utmost acumen and
ingenuity.
With respect to some particular solid parts of
the body, such, for example, as the epidermis,
the nails, &c. there exists indeed not a shadow of
doubt, but that they are gradually destroyed and
again repaired; and with regard to the destruction
or waste and subsequent reparation of the bones
themselves, the testimony will appear equally plain
and conclusive, to any one who may consider with
attention the result of the well known experiments
made by feeding warm-blooded animals, for some
time, on the root of the rubia tinctorum, or who
may take the further trouble of contemplating
attentively the phenomena exhibited by certain
large plain bones, especially those of the cranium,
which in extreme old age become remarkably
attenuated, or diminished in thickness, in conse-
quence of the scanty nourishment with which they
are supplied at that period of life.
Upon the whole, if I be capable of judging
rightly, those solid parts appear to be not only
gradually consumed, and again repaired, by the
[Seite 86] faculty of nutrition, but possess also a vis repro-
ductiva, or power of re-production. This latter
is indeed a surprising faculty, destined not only
to make restitution for the uniform removal of
minute atoms by the necessary action of the animal
economy, but also to repair the incidental loss of
larger parts (suffered in consequence of external
injuries, wounds, &c.), by a perfect restoration of
the substance of which the body has been thus
forcibly deprived. That such a power does un-
equivocally reside in the bones, and a few other
parts, of which we have just spoken, is with me
too well ascertained and substantiated to admit of
a doubt.
But on the other hand, from a variety of obser-
vations and experiments which I have made both
on man and other warm-blooded animals, this
power of reproduction appears to reside in scarcely
any other solid parts of the body than such as are
endowed with contractility alone, without possessing
at the same time any of the other vital energies,
such as irritability, sensibility, or finally, specific life.
Of those parts of the system therefore (which
possess the more exalted kinds of vital energy),
the staminal balls appears to me to consist of a pe-
[Seite 87] rennial parenchyma, which is subject neither to
genuine mutation nor decay, but only liable to
certain vicissitudes in point of bulk, that are pro-
duced in the following manner, namely, when
the process of nutrition is conducted with suffi-
cient activity and vigour, the cellular interfaces of
the parenchyma, being uniformly filled with the rich
and plastic lymph of the blood, are, of course, dis-
tended, and the parenchyma necessarily enlarged;
but when, on the other hand, nutrition goes on
less favourably, these same interstices, being in a
great measure deprived of this nutritious lymph,
fall into a state of collapse, and the parts become
consequently diminished in size.
With respect to this plastic lymph (of the dig-
nity and importance of which we have spoken
fully on a former occasion), as it assumes with
great facility the appearance and nature of genuine
cellular membrane, so it appears to constitute ge-
nerally the principal nutritious matter of the
whole system, and is conveyed to every part of the
body by means of that infinitude of minute blood-
vessels, to which we have so often called the
reader’s attention.
During the time of the body’s advancement in
growth, it appears to possess certain peculiar or
specific powers, by the aid of which the lymph,
being deposited from the evanescent extremities
of the sanguiferous vessels, into the surrounding
cellular membrane, is duly arranged, and com-
pletely assimilated to each particular portion, and
kind of parenchyma. To the head of these specific
powers, must we in part refer that particular law
of affinity, by means of which the partes similares
of the system attract and appropriate to themselves,
the homogeneous elements of the nutritious lymph,
more especially such of them, as possess reciprocal
and kindred propensities; and to the same head
may we also in part refer that nisus formativus, of
which we will have occasion to speak more fully
hereafter, and to which must be attributed, the
just and specific application of the rude, and hi-
therto formless, elementary matter, and its subse-
quent organisation and arrangement into the form
and figure of its peculiar destination.
It is, I presume, from the joint co-operation of
both the preceding powers, that we must princi-
pally derive the nutrition of those parts of the
body, which are not proximately supplied with any
[Seite 89] blood vessels at all; such as the nails, hairs, &c.
and which are, notwithstanding, generated at first,
by a very powerful and truly infallible nisus or ex-
ertion, are afterwards advanced in magnitude, and
regularly supported by nutriment throughout the
whole of life, and, finally, if by accident removed,
are again readily restored by the astonishing
efforts of the vis reproductiva.
Although the preceding appears to be a general
breviate account of the process of nutrition, yet,
on the other hand, it is evident that there exists,
in different individuals, a great many varieties,
with regard to the degrees and modes in which
this function is discharged. Thus, for example,
in proportion as a more lax or more close apposition
and union of the nutritious matter are effected, the
texture of the parts themselves is rendered more
dense or delicate, and hence also seems to origi-
nate the difference between the specific weight of
human bodies; in which respect it is well known,
not only that man differs from man, but even
nation from nation: in testimony of this truth it
may be sufficient to adduce even a solitary example
from among certain northern tribes, namely, the
Jukutae, the Buratae, &c. people highly conspi-
cuous on account of the remarkable and truly sin-
gular levity of their bodies.
Besides those juices destined for
the important process of nutrition, there are also
in the animal system other humours, of a very
different order and character, which are extracted
for various purposes from the exuberant fountain
of the blood. These humours owe their exis-
tence to the process of secretion, than which no
function is less understood by physiologists; a
truth mentioned as a subject of just regret, both
by the immortal Haller and other preceding
writers.
The secreted humours, appear, in one point of
view, to be so extremely diversified in their na-
tures, and, in another, to bear so striking an affi-
nity to each other, that it is not possible to reduce
them to any, save highly arbitrary, classes. If,
however, in treating of these humours, we found
our divisions of them on the less and greater
changes to which their elementary parts, (con-
[Seite 91] tained in the mass of blood), are subjected in the
secretory organs, they may be aptly enough enu-
merated in the following order.
First, the milk, a fluid which we think proper
to place at the head of our census or enumeration,
because it may be considered, in some measure, as
renovated chyle, and appears to be secreted, by
the most simple process, from the blood, to which
the chyle had been recently united.
Secondly, the aqueous fluids; such, for exam-
ple, as the humours of the eye, and the tears:
to the same head must we refer in like manner,
the sweat; and also, (if our opinion be not un-
founded), that halitus which is contained gene-
rally in the interstices of the cellular membrane,
as well as in the cavities of the thorax and abdo-
men: this vapour appears to differ but very little
either from the liquor of the pericardium, or from
that subtle halitus by which the ventricles of the
brain, and the pituitary sinuses of the cranium are
preserved in a state of perpetual humidity.
Under the same head of aqueous fluids, it is
likewise common to arrange the urine, although
this is doubtless a liquid possessed of some singu-
larly striking and peculiar properties.
Of a less compound nature are the salivary
humours, which, in office, are subservient to mas-
tication, to digestion, and to chylification.
Thirdly, the mucagenous fluids, which invert
and lubricate the cavities of most of the viscera,
that are destined to the performance of the natural
and genital functions, and also the internal surfaces
of all the aerial avenues belonging to the system,
such as the nares, the larynx, and the aspera
arteria.
Of a nature not widely different from the fore-
going, is that portion of mucus which covers the
internal segment of the eyeball; as well as that
which is spread immediately beneath the epi-
dermis.
Fourthly, the adipose humours are, in particular,
(besides the common fat itself), the medulla of
the bones, and the smegma or oily covering of the
skin, to which may be added the cerumen aurium,
or waxlike substance inverting the external ave-
nues of the ears.
Of a nature nearly related to the foregoing, is
that unctuous secretion, so evident on the glans
penis of the male, and about the rima or os exter-
num, in the genital organs of the female.
Under the same class may we also arrange that
oily substance, with which the glands of Melbo-
mius furnish and anoint the eyelids.
Fifthly, what are commonly denominated by
physiologists gelatinous fluids, examples of which
we have in the liquor amnii, and unguen of the
joints. Respecting the nature of these fluids,
however, we are not yet possessed of a sufficient
number of well authenticated facts to give birth
to unequivocal and satisfactory conclusions: a
similar observation may also be made, respecting
that uninvestigated and anonymous humour, which
the female uterus discharges during the ardent
glow of the venereal orgasm.
We remain also as yet, in a state of equal un-
certainty respecting the nature of that fluid, which
is lodged, during the first months after conception,
between the chorion and amnios; of that which
is contained in the umbilical vesicula or pouch of
the embryo in its tenderest state; and also of that
which is interposed between the three vessels that
constitute the umbilical cord.
The liquid enclosed in the vesiculae graffianae of
the female ovary, and also the liquor of the pros-
tate gland, appear to be of a truly serous or albu-
minous nature.
Sixthlly, the male semen appears to be a humour
so remarkably singular in its nature, as not to
admit of classification, nor even of comparison,
with any other.
And lastly, with regard to the bile, there is
equal room for the admission of a similar obser-
vation.
That the foregoing secreted humours, so ex-
tremely diversified in their natures and habits, can
neither be derived from the mass of blood by the
same individual process, nor by organs of the same
kind, is a proposition too self-evident to stand in
need of, or indeed leave room for, any farther
confirmation. Among these humours, there ob-
viously exists this memorable variety, namely, that
while some of them are secreted and conveyed
from the blood through a shorter route, others
again, are more elaborately prepared, by being
carried onward through tubes of greater longitu-
dinal extension.
Of all the modes of secretion, that must doubt-
less be considered as the most simple, in which the
secreted humour appears to transude immediately
through the coats of the arteries, by what physi-
[Seite 95] ologists call diapedesis. Instances of this mode we
have in the secretion of the fat, and of the medulla
residing in the bones, &c.; and, finally, it appears
to be by a modification of the secretory process,
not greatly dissimilar to the foregoing, that the
gastric liquor, the intestinal liquor, &c. are pre-
pared and discharged into the cavities of their
respective viscera.
The mechanism of secretion appears to be more
compound, where that process is performed by
means of glands, under which denomination we
generally include even follicles and cryptae them-
selves; such, for example, as are easily discover-
able in the fauces; and which physiologists gene-
rally designate by the name of glandulae sim-
plissimae.
We bestow, with propriety, the denomination
of secreting glands, on those bodies which, (to
distinguish them from the conglobate, belonging to
the lymphatic system), are called conglomerate; ex-
amples of which we have in the salivary glands, in
the pancreas, in the lachrymal glands, and in the
mammas, or breasts of females. The foregoing
glandular bodies are furnished with excretory
ducts, which are, composed of tubes or canals
running immediately from their larger lobes: these
[Seite 96] lobes, on being submitted to farther examination,
are found to be made up of smaller lobules, re-
specting the internal structure of which, there for-
merly existed very warm controversies in some of
the most celebrated schools of medicine. Malpighi
considered the small miliary globules, which may
be readily demonstrated in the greater part of
them, to be nothing else than genuine acini or
kernels, containing, each one, a minute cavity in
its centre. While Ruysch contended, on the
other hand, that those hypothetical excavated
kernels were nothing more than globular convo-
lutions of extremely fine blood vessels; which lat-
ter opinion, is doubtless founded on by far the
most unequivocal and substantial testimony, as
we readily learn from well conducted anatomical
investigations, more especially from successful
injections, and the assistance of glasses.
Nor does this structure (if indeed we keep out
of view the peculiar parenchyma of each parti-
cular viscus), differ much from, but appears rather
to shed a considerable gleam of light on, the struc-
ture of certain other secreting viscera, particularly
on that of the liver and kidneys, in which late ex-
perimenters have been able to demonstrate, with
the utmost perspicuity, certain spherical bodies
entirely similar to the globular convolutions of
[Seite 97] Ruysch, or the kernel-like substances of the cele-
brated Malpighi. For, in what is called the cortical
portion of those viscera, minute ramifications emerg-
ing from the sides of the small capillary arteries, be-
come presently convoluted, in such a manner, as to
form little vascular balls, which thus appear to hang
by those ramifications of which they are composed,
like so many small berries or grapes supported by
their footstalks. From these minute vascular balls
originate first, that very subtle and colourless
order of vessels immediately destined for the busi-
ness of secretion. (respecting the origin of which,
from the evanescent terminations of arteries, we
transiently spoke on a former occasion, (§ 79.
81.); and secondly, the incipient radicles of veins,
into which the minute arteries are themselves
continuously reflected, and which conduct back
to the venous trunks, the residue of the blood
now deprived of those elementary particles neces-
sary to constitute the fluid recently secreted.
Finally, certain other parts of the body, appro-
priated entirely to the business of secretion, are
distinguished again by different and remarkably
peculiar, species of organization; thus the male
testes, for example, are wholly composed of no-
thing else than close and mazy convolutions of
very lengthy and numerous blood vessels, &c.
We come now to the consideration of the pe-
culiar causes, by the operation and efficacy of
which those determinate and specific humours are
secreted in these corresponding determinate and
specific organs: this is indeed the Gordian knot –
this is by far the most difficult point of disquisition
in the whole doctrine of secretion – that point
which numerous doubts and difficulties yet invest.
It appears indeed to be a truth ascertained and
established beyond the faintest shadow of a doubt,
that the leading, and what may be called the
proximate cause of most of the secretions, must
be sought for in the internal structure of the se-
treting organs themselves: under this head we
must particularly consider, in the conglomerate
glands and other secreting viscera, not only the
peculiar distribution and direction of the extreme
blood-vessels, from which the humours are se-
creted, but also the parenchyma, so uniformly
proper to each secreting viscus, that in many of
them it can be instantly known and distinguished
at first sight from all other kinds or species of
flesh (§ 27).
It is also an opinion extremely probable (in
support of which we have advanced, on former
[Seite 99] occasions, several arguments not easily refuted),
that the secreting viscera, besides their peculiar
parenchyma, possess also what we have taken the
liberty to call a vita propria, i.e. a specific or
exclusive kind of vital energy, essentially different
from what we denominated the three common
energies, namely, contractility, irritability, and sen-
sibility.
But further, if my views of the subject be in
any measure just, the absorbent system appears to
contribute also a very important part towards the
promotion of the several secretions: thus, from
each of the secreting viscera certain appropriate
branches of this system absorb and re-convey to
the blood-vessels larger or smaller portions of each
of the several humours to which these viscera give
origin; the uniform consequence of which is,
that the blood becomes literally impregnated with
the contagion of every humour secreted in the
different parts of the body, e.g. with bile from
the liver, with semen from the testes, &c.
Thus there appears to exist, in the system de-
stined for the business of secretion, a perpetual
routine or circulation, so that the elementary
parts of the humours already secreted being in-
cessantly conveyed from the secreting organs
[Seite 100] themselves, are united afresh to the mass of blood,
and on their subsequent return to their parent
organs, in conjunction with the sanguineous cur-
rent, are again more easily attracted by the se-
creting vessels, in consequence of a peculiar law
of affinity, and have also a power of drawing
along with them those parts of the blood that
are most homogeneous in their nature, and for
which they consequently possess the highest de-
gree of attraction.
To facilitate the secretion of certain humours
of the body, adequate provision is made by the
production of specific qualities, in those particular
portions of the blood from which they are to be
proximately derived: thus the bile is secreted
from the blood of the vena portarum, a portion
of fluid highly impregnated with phlogiston, fur-
nished in profusion by the abdominal sources, from
which this blood immediately originates.
I pass in silence over certain other co-operating
aids, which act in subservience to particular secre-
tions, as congestion and derivation, so evidently
efficacious in the secretion of milk, with other in-
stances of a similar nature.
Among the humours thus secreted by the or-
gans which we have just described, and by the
powers or causes just enumerated, it may be ob-
served that the following difference afterwards
exists, namely, while some of them drop imme-
diately from their secreting organs into the places
of their ultimate destination, in which they are to
perform their specific functions, others again are
conveyed to appropriated receptacles, in which
they are retained for some time, and thus farther
matured previously to their final elimination from
the system: of this last description is the milk
which stagnates in the lactiferous ducts, the urine,
the bile, and the semen masculinum, which are
subjected to retention in their vesicular receptacles,
and finally, the serum, contained in those vesicles
which were first discovered by de Graaff in the
ovaria of the female.
Besides the nutritious juices and the
secreted humours destined for further services in
the animal economy (§ 4.), the blood furnishes
also materials for the formation of certain useless
and superfluous liquids, that are intended to be
entirely eliminated from the system, and are from
thence vulgarly called excrements of the second di-
gestion. These excrementitious liquids are of two
kinds, one of which is exhaled by the process of
perspiration, and has already engaged our parti-
cular attention; the other is the urine, a liquid
secreted in those glands denominated kidneys.
The kidneys are two viscera situated behind the
peritoneum, on each side of the spine, and in the
upper part of the lumbar region: Although their
figure is generally somewhat slatted, yet it is pro-
per to observe, that both in this respect, and also
in point of number, they are subject to more va-
rieties than any other viscus belonging to the hu-
man body: they hang by vessels commonly called
[Seite 103] emulgents (remarkably large in proportion to the
magnitude of the parts on which they are distri-
buted), and are cushioned round by fat of a seba-
ceous consistence (§ 38).
They are invested by a proper membrane, of
an elegant vascular structure: each one of them,
especially during the period of infancy, appears to
be composed of about eight, or somewhat more,
kidney-form lobes or subdivisions; each of which
consists again (according to an opinion formerly en-
tertained and taught by Ferrein), of about seventy
or eighty fleshy radii, which that physiologist
called white pyramids.
If the kidney be dissected or divided from its
convex dorsum towards its concave pelvis, it ex-
hibits in its composition two kinds of substance;
one forming its circumference, and therefore de-
nominated its cortical, the other constituting its
centre, and hence called its medullary, portion.
Each portion abounds with sanguiferous arte-
ries and veins; besides which, the external cortex
is also furnished with an additional order of very
minute colourless vessels, destined to secrete the
urine: while the medulla contains also vessels of
[Seite 104] a similar description, intended to carry it onward
when secreted.
Those secretory ducts originate, in the manner
already described (§ 471.), from the small glo-
bular convolutions of capillary arteries that are
every where interspersed throughout the cortex
of the kidney: those ducts constitute indeed by
far the greater portion of the cortical substance
of the kidney, and may be very easily distinguished
by their singular meanderings and intricate mazes,
from the small conducting tubes of Bellini, in which
they finally terminate. These tubuli Belliniani
(as they are frequently termed) pass by a direct
route from the cortical, and enter the medullary
substance, of which they constitute by far the
greater part; and uniting afterwards by reiterated
coalitions into a small number of narrow trunks,
finally perforate, by their extreme orifices, in a
sieve-like manner, the several papillae contained in
the renal pelvis.
The papillae correspond for the most part to the
number of lobes, of which we already said each
kidney is composed. The urine that is secreted
in the colourless vessels of the cortex, and after-
wards conducted through the tubuli Belliniani of
the medulla, these papillae discharge into their
[Seite 105] corresponding infundibula, which form by their
subsequent confluence the common pelvis.
The pelvis is continued into the ureters, which
are membranous canals, exquisitely sensible, and
defended internally by a complete investiture or
lining of mucus; they are capable of extreme di-
latation; in man they are here and there uneven
in the width of their cavities, and are at length
inserted into the posterior surface, not far from
the neck of the urinary bladder. This insertion
is effected in such a manner, that the ureters do
not immediately perforate the parietes of the uri-
nary cyst, but descend a short distance between
its muscular and nervous coats (which are here
possessed of more than ordinary thickness), and
open finally into the cavity of this organ by ob-
lique orifices. By means of this structure, ade-
quate provision is made to prevent the urine, that
has once entered the cavity of the bladder, from
being forced to return again into the ureters by
an inverted or retrograde motion.
In an adult subject, the urinary bladder is in
general sufficiently capacious to contain about two
pounds of urine; its fundus or bottom, which in
she faetal state terminates in the urachus, and also
[Seite 106] its posterior side, are invested by the peritoneum;
as to its remaining membranes or coats, they bear
a general resemblance to those of the stomach, of
which we have already spoken.
The muscular coat consists indeed of interrupted
bands of fleshy fibres, that surround the cyst,
forming at the same time various irregular decus-
sations or intersections, which are different in dif-
ferent subjects: this muscular coat physiologists
denominated detrusor urinae, while they designate
by the name of sphincter vesicae, those orbicular
fibres that partially surround the neck of the blad-
der, though they are very inconstant and irregu-
lar, both with respect to their figure and origin.
The nervous coat bestows on this membranous
viscus also the principal part of its strength and
firmness.
Finally, the internal coat, which is considered
by physiologists as a process or continuation of the
epidermis, is defended by a complete covering of
mucus, especially round the neck of the bladder.
Besides those public and well known routes of
the urine, of which we have already spoken, it
appears probable from several phenomena, that
[Seite 107] there exist also certain secret avenues, which lead
immediately from the intestines to the uropoietic
organs. For the speedy discharge of certain
drinks from the urinary emunctory, so frequently
imbued with the odour, tinctured with the colour,
and characterized by other specific qualities of the
aliments recently taken in, will scarcely admit the
belief, that these liquids had performed, in so short
a time, the customary long and circuitous route
through the thoracic duct and sanguiferous sys-
tem: to the foregoing circumstance we may add
an account we have read, of the urine having
been found covered with oil, that entered into the
composition of an enema, which had been previ-
ously and recently thrown into the intestinum rec-
tum. It is, on the other hand, a circumstance
well known to physiologists of the present day,
that very striking and numerous anastomoses oc-
cur between the lymphatic vessels of the intes-
tines, and those of the kidneys. Lastly, it is now
unequivocally ascertained and confirmed by live
dissections, that if both ureters of a dog be tightly
enclosed in ligatures, and his bladder perfectly
evacuated of its contents, this latter organ will,
notwithstanding, in the term of three hours after-
wards, contain a certain quantity of urine; while
at the same time the usual avenues of this fluid,
namely, the ureters, are completely obstructed, as
is evident from this circumstance, that above the
[Seite 108] ligatures these tubes suffer vast distention from the
accumulated urine.
But through whatever avenues the urine has
been conveyed to the bladder, its gradual accu-
mulation in that organ excites an uneasy sensation,
which becoming urgent and troublesome (§ 331.)
potently solicits its final elimination, through an
emissary or sewer destined for that particular pur-
pose, namely, the urethra. This excretory canal
is subjected to a variety in its conformation, found-
ed on the diversity of the sexes, of which we will
speak more amply when treating professedly of
the sexual functions.
In order to evacuate the bladder, it is necessary
to overcome the contraction of its sphincter, by
the exertion of its own detrusor (of which we for-
merly spoke) (§ 486.), aided by the co-operation
of the abdominal muscles, and those subservient
to the process of respiration; to which, in males
of the human species, we may add, lastly, the
action of the musculi acceleratores, which forcibly
ejaculate, per saltum as it were, even the residuary
drops of urine that may be occasionally lodged in
the bulb of the urethra.
As to the nature of the urine itself, it is subject
indeed, to an infinitude of varieties generated by
the circumstances of age, and season, but, above
all, by the longer or shorter term of time, subse-
quent to the previous use of food and drink, the
discharge of this fluid occurs; to which may be
also added, the quality of the aliment previously
used, &c. In general, however, when we exa-
mine the urine which is discharged by a healthy
human adult, immediately after found and tran-
quil sleep, we discover it to be a watery liquid, of
a nidorous smell, and citron colour, containing in
its aqueous medium, (as in a common vehicle)
various elementary substances, especially earthy
and saline, which bear different proportions to
each other in different individuals, and even in
the same individual at different times and under
the influence of different circumstances. Of the
terrene elements the most abundant is, in general,
calcareous earth, which is not unfrequently found
in the urinary passages under the form of calculi,
but which is, notwithstanding, extremely variable
and inconstant in its quantity. Of all the saline
matters, that most worthy of being mentioned, is
the essential and native salt of urine – called also,
microcosmic salt, fusible salt, &c. This saline sub-
stance contains, in a greater proportion than any
[Seite 110] other part of the human body, the celebrated
phosphoric acid chemically espoused to the volatile
alkali.
Those functions of the human body,
in the consideration of which we have been hi-
therto engaged, are indeed possessed, and exercised
in common, by the individuals of each sex: with
respect to the mode, however, in which some of
them are performed, there occur between the
two sexes no inconsiderable degrees of difference.
Of this difference, it may be proper briefly to
enumerate the leading points, previously to our
entrance on the consideration of what are denomi-
nated the sexual functions.
To speak, then, in general terms, each sex
possesses and exhibits its own peculiar habit, which
differs considerably from that of the other. In
[Seite 111] the human subject after birth, this difference of
habit is distinctly observable; but during the ten-
der foetal state, is scarcely to be distinguished,
unless by more close and pointed attention;
neither indeed, in this state, can the external
organs of generation themselves be discriminated,
on a transient and superficial view, owing to the
extraordinary magnitude and prominency of the
female clitoris, and the very diminutive size of the
male scrotum.
During the period of infancy this difference of
the general habit, depending on the diversity of
sex, makes only a slight impression on the ob-
server; but becomes gradually more and more
obvious and striking till the full completion of the
years of puberty, at which period, the general
conformation of the female body, its tenderness,
its softness, and the usual inferiority of its stature,
contrasted with the athletic and robust body of
the male, exhibit this general habitual difference
in the most striking point of view.
Similar to the difference that occurs between
the external habits of body, that characterise the
two sexes, is that which is observable in the bones
[Seite 112] themselves. These solid portions (all other cir-
cumstances being alike) are evidently much more
smooth and round in females than in males; the
cylindrical bones, in particular, are more slender
and delicate, and the plane ones more attenuated
or thin, in the former, than in the latter sex; not
to mention the peculiar diversities of certain re-
markable bones, particularly those of the thorax
and pelvis, with the clavicles, the femora, &c.
With respect to the soft parts of the body, we
may observe in general, that in females, the cel-
lular membrane is more lax, more pliable, and
consequently more readily dilatable in the state of
pregnancy: while the skin is more tender, fair
and beautiful, in consequence of the immediate
substratum of fat.
The hair of the head is generally of a greater
length in females than in males, while at the same
time, certain other parts of the body which in the
latter are rough and hairy, are in the former
either perfectly smooth, as the chin and breast;
less hairy, as the perineum; or planted with only
a very tender and soft down, as the arms and
legs.
When speaking of the diversities of particular
functions, we must not silently pretermit the pulse,
which (other circumstances being alike) is more
frequent in females than in males, (§ 109). In
the former, the thorax is subjected to a greater
degree of motion, (especially at its superior part,)
than in the latter; the os hyoides is much smaller,
the larynx is less capacious, and hence the voice
more shrill.
With regard to the animal functions, it is ne-
cessary to observe in general, that in females the
mobility of the nervous system is much greater
than in males, the irritability is more exquisite;
and the propensity to commotions of the mind,
more prompt and spontaneous.
As to the natural functions, the appetite for
food is weaker in the female, than in the male
sex; while, on the other hand, the increase of the
body is more rapid in the former, and the state of
puberty and mature growth attained at an earlier
period.
But by far the greatest and most important
distinction of the sexes is derived from the genital
functions themselves, the male being furnished
with a power of foecundation, and the female with
that of conception. A farther investigation of these
powers shall engage the greater part of our atten-
tion, throughout the remaining pages of this
work.
The genital liquor of the male is
prepared by the testes, two bodies suspended in
the scrotum by their spermatic cords, and (besides
the lymphatic veins with which they abound in
profusion), composed chiefly of three kinds of
vessels.
These are first, the spermatic artery, which in
proportion to its slender diameter is said to be the
longest of all the arteries belonging to the human
[Seite 115] body: it in general conveys the blood immedi-
ately from the abdominal portion of the aorta
itself, to the body of the testis.
Secondly, the ductus deferens, which carries to
the visiculae seminales, the semen when once se-
creted from the arterial blood.
And, lastly, what is commonly denominated the
pampiniform plexus of veins, the function of which
is to receive and convey to the cava or emulgent
vein, the blood that remains after the process of
secretion is accomplished.
The testes are not, from the time of their
earliest formation, suspended in the scrotum, as
represented in the above description: thus in the
male foetus, while yet in a very tender and imma-
ture state, those glandular bodies occupy indeed
a very different situation, the reason and successive
changes of which were first accurately investigated
und detailed by Haller, at Gottengen in the year
1749, but were afterwards explained by other
writers on principles so different from each other,
as to have given rise to various controversies of
some weight and importance. Of the situation
and changes of the testes in the foetal state, I am
prepared to lay before the reader a brief, though
[Seite 116] comprehensive account, – the spontaneous result
of numerous observations made on nature herself,
during a remarkable series of dissections of male
embryo’s, in which I engaged for the express
purpose of shedding light on this subject so inte-
resting to physiologists.
On opening the lower abdominal region of an
immature foetus, we discover in each groin, near
what is called the ring of the oblique muscles, a
very narrow orifice in the membrane denominated
peritoneum; this orifice is the threshold to a strait
avenue or alley, as it were, that leads through the
abdominal ring itself, and terminates afterwards
in a peculiar bullous or bubble like sack: this
sack extends without the abdominal cavity, looks
towards the scrotum, is interwoven with cellular
fibres, and destined for the future reception of
the testis.
At the very posterior margin of this small
abdominal orifice, the peritoneum sends off an-
other process, which mounts upwards, and in the
tender foetus represents, in the greater part of its
course, a longitudinal fold: from the basis of this
process a slender cylinder, or rather inverted cone
ascends, und forms at its summit, which regards
[Seite 117] the inferior margin of the kidney, a small blister
or sack-like termination; in this sack the testis
and epididymis are enclosed; so as to resemble,
at first sight, a small berry resting on its footstalk,
and appear, at the same time, to hang loosely into
the abdominal cavity somewhat like the liver or
spleen (§ 404).
The vessels which are afterwards to constitute
the spermatic cord, are, at this very early period,
seen running behind the extremely tender and
pellucid peritoneum, so that the spermatic artery
and vein run in a descending direction along the
sides of the spine, while the vas deferens bending
somewhat inwardly towards the neck of the uri-
nary bladder, stretches along the loose cellular
membrane, which is situated behind the perito-
neum, and both enter the body of the testis in
that peritoneal plica or fold of which we have
already spoken.
From about the middle stage of pregnancy, the
testes begin to sink downward by degrees, so as
gradually to approach the narrow orifice of the
peritoneum, which has been already mentioned.
At the same time, the foregoing peritoneal fold,
with its cylindrical attachment, are wrapped up
[Seite 118] by degrees, till the testis finally rests on the very
mouth of the preceding canal.
When in the foetus, now advanced to a higher
stage of maturity, the testis is fully prepared for
a final descent, the orifice, hitherto so contracted
or narrow, suffers such a remarkable dilatation,
that the testis is at full liberty to enter with facility
the opening that leads out of the abdomen as well
as the ring by which this opening is surrounded,
to pass onward through the whole length of the
canal, and thus plunge headlong, as it were, into
the blister-like sac of which we have already spo-
ken. The testis having finally accomplished its
descent, the peritoneal opening is soon after closed
in the most complete manner, and even subjected
in a short time to a perfect adhesion of its sides, so
that in the stage of infancy, scarcely a wreck of
it is left, to point the enquirer to the place of its
former existence.
The more gradual and slow the movement of
the testis (while yet in the abdominal cavity) to-
wards the orifice of its egression, the more sud-
den and instantaneous appears to be its act of
transition through the abdominal ring. For in
the dissections of mature foetuses, it is by no means
[Seite 119] uncommon to discover the testis either as yet in-
cumbent on the peritoneal opening, or else statio-
nary in the groin, after having recently passed the
abdominal ring: but once only was I so fortunate
as to have an opportunity of observing the right
testicle of a twin-foetus (of which a complete
drawing has been given), at the very moment of
its passage through the abdominal ring: the gland
appeared to have been very tightly embraced and
strangled, as it were, by the surrounding parts,
and was apparently in complete readiness to
emerge from the abdomen into its destined sack;
a transition already accomplished by the left tes-
ticle, that had just escaped from the ring, the ori-
fice of which had again resumed its former imper-
vious state.
This remarkable descent of the testes along the
groins, does not appear to be exclusively confined
to any particular period of time: it occurs for
the most part, however, about the last month of
pregnancy: although these glandular bodies are
not unfrequently sound either in the abdominal
cavity itself, or in the superior part of their in-
guinal route, even in infants after birth. For the
testicle, after its entire escape from the abdomen,
has still a further-stage of its journey to perform,
namely, its final descent along the groin into the
[Seite 120] scrotum, in company with the small sac by which
it is enveloped.
That the foregoing is indeed a true account of
the progressive movement of the testes in their
descent from the abdomen into the scrotum, I
have had sufficient opportunities of ascertaining
from repeated observation. To develope the
causes and energies by which this astonishing de-
scent is accomplished, appears to be indeed attend-
ed with difficulties of the utmost magnitude. For I
am daily more and more convinced, that neither of
those powers to which this descent has been hither-
to ascribed (such, for example, as the action of the
cremaster muscle, the action of the diaphragm, or
the contractility alone of that cellular and tendi-
nous intertexture, which adheres to the processes
of the peritoneum, and is usually denominated
gubernaculum Hunterii, &c.), is sufficient to ex-
plain a movement of such extreme singularity,
especially that part of it relating to the immediate
transition of the testis through the narrow abdo-
minal ring, to which the reader’s attention has
been so frequently solicited: while I am impressed,
on the other hand, by a thorough conviction,
that this whole process exhibits the most unequi-
vocal and striking example of what we have de-
nominated specific life, without the peculiar opera-
[Seite 121] tion and aid of which, it is scarcely possible to
solve the several phenomena of a transition so ex-
tremely singular in its nature, and so widely dissi-
milar to all other movements and functions that
occur in the whole animal economy.
The involucra by which the testes are invested,
after their final completion of the foregoing route,
may be aptly enough divided into common and
proper.
The only involucrum common to both these
glandular bodies is the scrotum. This is a sac,
consisting of a tender portion of cutis expanded
over a thin substratum of fat, and possessing a pe-
culiarity that does not reside in any other part of
the common integuments of the body, namely, a
power of changing, in a very remarkable degree,
its usual habit and appearance: thus, it sometimes
depends loose and flaccid, and again (especially
under the impression of the venereal oestrum, or
in case of exposure to cold), becomes constricted
and rigid, as it were, and is then particularly
marked by furrows and diversified rugosities.
Of those involucra which are proper to each
testis, that placed immediately beneath and within
[Seite 122] the scrotum, is called the tunica dartos: this coat
possesses a very peculiar and vivid contractility, by
which Winslow, Haller, and other celebrated cha-
racters have been so far deceived, as to bestow on
it the nature and energy of a muscle.
This is succeeded (after a voluminous and soft
stratum of cellular membrane), by three separate
vaginal coverings, which were first accurately
traced and distinguished by the ingenious and in-
defatigable Neubauer.
Of these vaginal coats, the exterior is common
to the testicle and spermatic cord, and has the cre-
master muscle attached to it by separate bundles
of fibres.
But the two interior are proper, one to the sper-
matic cord, and the other to the testis itself; of
these the latter adheres, for the most part, by its
fundus to the common tunic, while its internal
surface is moistened by a lubricant fluid, some-
what after the manner of the pericardium.
The origin of those vaginal tunics which has
given rise to such a variety of controversies among
physiologists, can, (if I be not greatly deceived),
[Seite 123] be without difficulty ascertained, from what has
been already said, when treating of the descent of
the testes.
Thus, the tunica communis, for example, origi-
nates from the descending (§ 502.) blister-like
sac or process of the peritoneum.
The propria testis, from that production of the
peritoneum, which mounting upward in the form
of a cylinder (§ 503.), invests the testis itself from
its earliest formation.
And, finally, the propria funiculi, from that
fold of the peritoneum, of which we have already
spoken, and the short cylinder in which it termi-
nates previously to its embracing the testis itself.
Immediately to the testis itself the tunica albu-
ginea is very closely attached, somewhat after the
manner of a cortical covering. From this tunic,
blood-vessels pass into the pulp or body of the
testicle, which consists indeed entirely of innume-
rable vessels, about a span in length, wound up
into small conglomerate lobules: these vessels, of
which the substance of the testicle is composed,
are both sanguiferous and secreting, the latter of
[Seite 124] which conduct the semen, when prepared, through
the vascular net-work of Haller, and the vasa
defferentia of Graaf, into the beginnings of those
cones that form the epididymis.
That body which ranges along the side of the
testis, namely, the epididymis, consists indeed of a
single vessel, about thirty feet in length, which at
one end (that for instance denominated its head),
is distinguished into about twenty small rolls or
cones, and at its other (inferior) extremity, called
therefore its tail, increases gradually in thickness,
and thus forms by its continuation the vas de-
ferens.
The two vasa deferentia ascending towards the
neck of the urinary bladder, and forming a junc-
tion beneath, or near to, the prostate gland, are
from hence bent backward, and expanded into
the vesiculae seminales; in such a manner, how-
ever, that these vesiculae, and the vasa deferentia
themselves, open by two common orifices into the
urethra, just behind the caput gallinaginis.
Finally, the vesiculae seminales themselves, are
attached to the posterior surface of the urinary
[Seite 125] cyst, near to the inferior extremity, or neck, of
that organ: they are imbedded in a profuse quan-
tity of fat, and from their diversified flexuosities
and numerous blind appendiculae that shoot oft
somewhat in the form of ramifications, resemble,
in their general appearance, two small intestines.
These vesiculae consist of two coats, almost of
the same kind with those that enter, as formerly
mentioned, into the composition of the gall blad-
der; thus, the first or external coat is more ro-
bust, and similar in its nature to such as are com-
monly denominated nervous; while the second or
internal abounds with minute cells and pits, and
is every where divided, by means of projecting
eminences, into minute purse-like cavities, per-
fectly similar to those that are so conspicuous
about the neck of the gall-bladder.
In those organs and vessels hitherto enume-
rated and described, there is, even from the ear-
liest years of puberty, a certain fluid secreted
slowly, and retained in small quantity, namely,
the semen masculinum; a liquor extremely singular
in its nature, and of the utmost dignity and im-
portance in the animal economy: it exhibits to
the eye a milky colour, emits an odour entirely
peculiar, possesses a mucoid viscosity, and is of
[Seite 126] such remarkable specific gravity, as to surpass, in
this respect, all other secreted humours belonging
to the animal body.
A peculiarity of this fluid, which must not be
passed over in silence, is, (as was first observed by
Lud. Ham at Dantzic, in the year 1677), that it
is peopled by a countless multitude of microscopic
animalculae, belonging to the same order with
those called infusoria, and possessing different
figures, as they appear in the seminal fluids of dif-
ferent animals. In man (and also in the male
ass) the seminal animalcules exhibit oval figures,
furnished with tails of extreme minuteness: these
animalcules are said not to be found in any, save
sound and prolific semen, so that they appear to
constitute a certain adventitious criterion of the
fertilizing maturity of this important fluid: we
have called the criterion derived from these ani-
malcules adventitious, and presume it is scarcely
necessary, at this enlightened period, to repeat,
that they should not be accounted the reservoirs
of the fecundating principle, much less should they
be considered as the germs of future homunculi,
since so many, and such weighty arguments and
observations have been lately advanced in sup-
port of a different doctrine.
This genital liquid being gradually collected in
the vesiculae, which we have already described, is
there retained till a future act of excretion. By
such retention it suffers changes very nearly re-
sembling those to which the bile is subjected in
consequence of a state of stagnancy in its cystic
reservoir; thus, being gradually robbed of its
aqueous portion, it is more and more inspissated
and approximated, as it were, towards a state of
concentration.
For as the testes generally, together with the
cords by which they are suspended, abound with
an astonishing assemblage of lymphatic vessels,
which serve to re-convey from thence to the
blood a portion of fluid, impregnated with the
spermatic contagion, and by this means aid and
facilitate the further secretion of semen, on the
principle, and in the manner formerly laid down
(§ 476.), so are the vesicula seminales themselves
also provided with vessels of the same kind, which
by absorbing the subtle, though inert water, ren-
der the residue of the seminal fluid more active
and efficacious.
On this subject I doubt much whether or not,
in a healthy man, any genuine semen be ever ab-
sorbed from the vesiculae seminales: – more still,
whether or not, as is sometimes alleged, semen
thus absorbed could be carried immediately into
the neighbouring sanguiferous veins: – but most
of all, whether or not such a seminal absorption
(admitting its real existence) could possibly act as
an antidote against excessive venereal propensities,
since it appears evidently, on the other hand, that
this same absorption would necessarily operate as
an exciting cause of unbridled and almost infuriate
lust: in quest of testimony to establish the truth of
this latter proposition, we need only attend to the
phenomena of such animals as experience the ve-
nereal propensity only at stated seasons of the
year, and compare them with the constitution of
those that have been reduced to the state of cas-
tration.
To me indeed it appears probable, that, for the
purpose of moderating libidinous desires, man is
endowed with a far different prerogative (not
conferred on any other species of animals with
which we are hitherto acquainted), namely, that
of nocturnal pollutions: these evacuations I there-
fore consider among the natural excretions of man
[Seite 129] – evacuations by which (as they occur at longer
or shorter intervals, according to the varieties of
temperament and constitution), he is relieved from
a troublesome and otherwise urgent impression
produced by an abundant accumulation of semen.
It must be observed, however, that the semen
masculinum is never excreted in a state of entire
purity, but is always blended with more or less of
what is usually denominated liquor prostatae (i.e.
the liquor of the prostate). With regard to the
external habit and appearance of this last men-
tioned liquid, it bears a very striking similitude to
the albumen or white of eggs. This peculiar
liquor derives its name from its immediate birth-
place or source, which is a body of considerable
magnitude, and of a singular and very compact
parenchymatous texture, situated between the ve-
siculae seminales and the bulb of the urethra, and
is usually designated by the name of glandula pro-
stata. The excretory avenues of this liquor have
not yet been satisfactorily investigated and ascer-
tained, unless (as appears probable) they commu-
nicate with the duct of the caruncula seminalis,
the orifice of which opens into the urethra be-
tween the two mouths of the avenues leading
from those minute vesicles destined for the recep-
[Seite 130] tion and temporary retention of the fertilizing
semen, (§ 516).
The urethra in man is destined as a common
conduit or emissary duct, to three different kinds
of fluids, namely, the urine, the semen, and the
liquor of the prostate gland. It is lined internally
with a mucus which originates from an immense
number of sinuses, that are every where dispersed
throughout its canal. It is surrounded by a sub-
stance of a spongy texture, to which are subjoined
two other bodies, similar in structure but far supe-
rior in size, (called corpora cavernosa), that con-
stitute the principal part of the male penis; an
organ which is terminated anteriorly by the glans,
and wholly invested by a very tender and pliable
portion of skin entirely destitute of all appearance
of fat. This skin forms the prepuce by its at-
tachment round the corona, or circular base of the
glans, and plays over this body with a free motion,
somewhat like the palpebrae over the ball of the
eye. The interior duplicature of the prepuce,
having assumed a different appearance, is reflected
over the glans itself, (somewhat like the adnata
over the eye) and is furnished around the corona,
with an immense number of the small glands of
Littrius, (analogous to the Meibomian glands of
[Seite 131] the palpebrae) that give birth to a matter of an
unctuous but very singular nature.
The male penis, thus organised and constructed
agreeably to the preceding description, possesses a
faculty of erection, i.e. in consequence of an
encreased congestion and impetuous effusion (for
congestion alone will not explain the phenomenon)
of blood into the corpora cavernosa, the penis
swells, becomes rigid, and changes its former
position, but suffers again a detumescence and
collapse by a reabsorption of the superfluous por-
tion of this distending fluid.
When the penis resumes its flaccid condition,
it suffers a singularly circuitous flexion, at the
place where it originates from the neck of the
bladder. In this state it is, indeed, extremely
well calculated for the excretion of real urine, but
quite unqualified for the emission of semen, as the
beginning of the urethra forms now a more acute
angle with the small orifices of the vesiculae semi-
nales.
When a gradual intumescence of the penis com-
mences, there occurs first an effusion of the liquor
[Seite 132] furnished by the prostate gland, which is often-
times eliminated unmixed, but scarely ever along
with the urine. Of this liquor the primary desti-
nation is, to be ejected, in conjunction with the
seminal fluid itself; either, that it may, by its
albuminoid lubricity, qualify the sluggish tenacity
of the latter fluid, and thus facilitate and promote
its ejection; or that it may itself contribute, in a
certain degree, towards the process of generation.
The emission itself of the male semen is excited
as well by the immediate impression arising from
an abundant accumulation of this fluid in its ap-
propriated receptacles, as by the genuine sexual
instinct; it is accomplished, first, by a very strong
erection of the penis, which, while it obstructs the
passage of the urine, paves as it were, on the
other hand, a more direct and ready way for the
transition of the semen; to which we may subjoin,
as co-operating causes, a certain spasmodic con-
traction of the vesiculae seminales, a convulsive
action of the levator ani, and acceleratores urinae,
and finally, a general succussion, of the whole ner-
vous system, gentle indeed in degree, and transient
in existence, but yet of an epileptic nature, and
considerably depressing, in its effects, on the ener-
gies of the system.
As the male organs of generation are
naturally calculated to give, so are the female to
receive, and in the two sexes these organs are, in
a general point of view, widely different from
each other. It must be observed, however, that
in the general structure of certain parts, these two
kinds of organs exhibit no small degree of reci-
procal similitude. Thus beneath the pubes (the
structure of which has been already a subject of
transient attention (§ 36.) the clitoris which lies
concealed in the superior commissure of the labia,
resembles the male penis in more respects than
one, but is not furnished with a urethra, is there-
fore imperforate, and, (when not of a preter-
natural proportion,) is remarkably small. It is
said, however, that this organ preserves, occasion-
ally, even in adults, the same proportional size,
which, as formerly observed, is so extremely
conspicuous in the clitoris of the female embryo,
(§ 492.) Hence appears, in all probability, to
have originated most of those obscene and fabulous
[Seite 134] stories, respecting the existence of hermaphrodites.
This organ consists also, like the male penis, of
corpora cavernosa, like it, is capable of erection,
like it, is invested by a prepuce, and furnishes,
finally, an unctuous matter not dissimilar to that
of Littrius, (§ 525).
From the clitoris descend the nymphae, acquiring,
also, occasionally, an enormous and preternatural
magnitude, (which excess has, in like manner, not
unfrequently given rise to extraordinary and fabu-
lous reports): they possess, in common with the
clitoris the most exquisite degree of sensibility;
and appear to give direction to the stream of urine
when discharged, as the orifice of the urethra,
(a tube extremely short in the female sex, and, in
the most highly finished and perfect examples,
ciliated or fringed in a very singular manner), lies
hid, as it were, in a fossa formed by their two
bases.
Beneath this orifice is situated the opening of
the vagina itself, environed by cryptae of various
kinds, such, for example, as the urethral lacuna
of Graaf, and the mouths of what are improperly
and even absurdly termed, the prostate glands of
Casp. Bartholin, &c. with the unguen-like mucus
[Seite 135] of which, these obscene parts are moistened and
lubricated.
Over the very threshold or entrance of the
vagina is expanded a weblike production denomi-
nated the hymen. This is a membrane, the exis-
tence of which in an unlacerated condition, is
considered as a sure badge of spotless virginity –
a membrane bestowed exclusively on the female
of the human species, and of which no physical
destination has been yet unequivocally ascertained.
The fringes or residual fragments of this mem-
brane, after laceration, are gradually converted
into what are denominated carunculae myrtiformes,
bodies quite indefinite in point of number.
From the immediate seat of these minute myrti-
form bodies ascends, between the urinary cyst and
intestinum rectum, the vagina, a tube composed
of a cellular parenchyma, interspersed with an
infinitude of small blood-vessels. At its inferior
extremity the vagina is encircled by a muscle
denominated constrictor cunni; more internally it
is lined by a very soft and delicate coat, which is
characterised by two extremely elegant columns of
rugae or wrinkles, namely, the anterior and poste-
[Seite 136] rior; from these columns a fine mucus is con-
stantly discharged, destined to lubricate the cavity
of this highly important canal.
The vagina, at its upper and interior end, re-
ceives and embraces, finally, the uterus, an organ
attached on each side to, and thus suspended by,
the ligamenta lata.
The cylindrical neck of this organ being thus
embraced, as it were, by the vagina, is perforated
by a narrow canal, which, like that of the vagina,
is impressed by a singular apparatus or arrange-
ment of rugosities, designated by the name of
arbor vitae: of this canal the two extreme orifices,
more especially the superior or internal, are over-
spread, for the most part, with a quantity of tena-
cious mucus.
The substance of the uterus is altogether sin-
gular in its nature, consisting of a peculiar paren-
chyma, very dense and compact, and interwoven
with an infinitude of blood-vessels (running in
serpentine mazes of astonishing intricacy) of which,
the veins are wholly destitute of valves. This
organ is doubtless furnished, in like manner, with
an apparatus of lymphatic vessels: it abounds
[Seite 137] with a countless number of nerves, through the
medium of which, it preserves such an astonishing
sympathy with the other parts of the system.
Externally the uterus is invested by the perito-
neum, while its minute internal cavity is lined,
especially at its fundus, by a very soft and tender
membrane, of a spongy texture, which, as some
physiologists allege, consists of colourless vessels,
while others pronounce it to be composed of lym-
phatic absorbents.
With regard to the muscular texture attributed
to this organ by some physiologists, and strenu-
ously denied again by others, I must take the
liberty of observing, that notwithstanding the
number of uteri which I have examined with the
utmost care and attention, both in an impregnated
and an unimpregnated state, (in each of which I
have had repeated opportunities of examining this
organ, not only in a prepared condition, but also
in subjects recently dead), I have never yet been
able to detect, in them, any portion that exhibited
obvious and unequivocal signs of muscularity. On
the other hand, I am daily more and more per-
suaded, that the uterus, possessing no muscular
fibres, is destitute also of true irritability (§ 307),
[Seite 138] and owes entirely to a vita propria, or specific life
(§ 47.), all its peculiar motions and functions,
which cannot, indeed, with the smallest semblance
of propriety, be derived from any of those ener-
gies that are common to what we formerly term-
ed the partes similares, or similar parts of the
body (§ 43, 46). So very singular and unac-
countable did the motions and functions of the
uterus appear to the physicians and philosophers
of ancient times, that they were led to consider
this organ as a smaller animal contained within a
larger.
From the angles on each side of the lacunar,
or fundus uteri, arise what are called the Fallopian
tubes. These are two very narrow and tortuous
canals, that run in the superior duplicature of the
ligamenta lata: they are similar in texture to the
vagina itself, except, that being internally destitute
of valves, they are lined with a kind of spongy
flesh, of a very soft and tender consistence.
The extreme orifices of these tubes, that regard
the abdominal cavity, besides being much more
capacious than those which open into the uterus,
are also edged round by fringe or finger-like sim-
briae, of a truly singular and elegant structure.
The offices which these simbriae are destined to
perform, in the business of conception, appear to
be indeed of no small degree of importance; thus
being rendered, during the venereal orgasm,
equally turgid with the tubes themselves, they
evidently embrace, in this state, the ovaria that
are situated in some measure beneath them.
The ovaria themselves, or the female testes, as
they were called previously to the time of Steno,
besides a tenacious and somewhat tendon-like in-
volucrum, consist also of a dense and decussating
cellular membrane, which incloses in each ova-
rium about fifteen of those minute bodies denomi-
nated the ovula, or little eggs of Graaf: these
ovula contain each a small vesicle, or rather drop
of serum, faintly yellowish in its colour, and of an
albuminous nature, which, if the recent ovarium
be immersed in boiling water, is reduced, like the
genuine white of eggs, to a state of complete co-
agulation.
An albuminoid drop of this kind appears to be
indeed the principal fluid which the female con-
tributes towards the process of conception; for it
appears extremely probable, that, throughout the
progressive course of what are termed the prime
[Seite 140] or better years of life, these small drops arrive at
complete maturity in gradual succession, so that
each one, in its turn, looks as it were through the
involucrum, by which the ovarium is enveloped,
till it is able finally to burst the parietes of its
prison, and thus be received by the abdominal
orifice of the Fallopian tube.
But besides this minute albuminous drop that
thus bursts from the volume of the ovarium, it
appears that there occurs also, during the vene-
real oestrum, an effusion of another liquor, which
ancient physiologists very improperly and errone-
ously denominated the female semen. Respecting
the nature, however, the sources, and the univer-
sal presence of this humour, we are able to pro-
pose nothing more determinate or satisfactory than
we can advance with regard to its destination
and uses.
A very frequent and highly import-
ant function of the uterus in the female of the hu-
man species is, to discharge monthly a tributary
effusion (called therefore catamenia), during the
tedious and momentous term of about thirty years.
This is a painful condition of existence, to which
nature has not subjected any other genus of her
subjects, throughout the wide and diversified range
of the whole animal kingdom; so that to use the
words of the eloquent Pliny ‘“the only menstruous
animal in nature is woman.”’ From this con-
dition, on the other hand, painful as it is, nature
has not exempted the females of any of the known
nations of the globe, but has stamped it with
the sacred character of an essential requisite – of
a genuine sine qua non, in rendering the female
sex competent to the propagation of their species.
The commencement of this singular function
generally takes place, in our climate, about the
fifteenth year of life, and is, for the most part,
preceded by various and unequivocal symptoms
[Seite 142] of plethora, such as congestion and anxiety about
the bread, sense of tension and weight in the lum-
bar region, lassitude or weariness of the limbs, &c.
On the first appearance of the catamenia, the ge-
nital organs, in the beginning of the attack, usu-
ally discharge a humour of a pale reddish cast;
this is gradually succeeded by a liquid of a more
intensely florid and sanguineous colour, which
terminates, at length, in an effusion of genuine
cruor or red blood. This spontaneous, though
gentle discharge of blood, is kept up for the
term of several days, and is, in the mean time,
accompanied by a gradual cessation of all those
distressing symptoms of which we have just exhi-
bited a partial detail.
From the time of its first occurrence, this con-
stitutional hemorrhagy (as it may, with sufficient
propriety, be denominated) becomes regularly pe-
riodical: thus its future paroxysms return uni-
formly about the expiration of every fourth week,
and at each recurrence, the evacuation continues,
at a mean calculation, about six days; during
which term, a healthy female is supposed to dis-
charge from eight ounces to an entire pound of
blood.
It is proper, however, to observe, that this func-
tion is subject, for the most part, to an entire in-
termission, during the state of female pregnancy,
and the term of maternal lactation.
The final cessation of the catamenia occurs after
their discharge has continued, at stated periods,
about the space of thirty years, which term of
time is completed, in our climate, about the 45th
year of life.
The sources of the catamenial discharge have
been referred by some to the vessels of the vagina,
and by others (with superior weight of evidence
on their side) to those of the uterus: for with
regard to those examples commonly adduced in
support of the former opinion, where women,
although pregnant, possessing an imperforated
uterus, or distressed by a prolapsus of that organ
in an inverted state, have notwithstanding men-
struated with uniform regularity, they tend to
prove nothing else than the powerful efforts of
the vis medicatrix naturae, which in cases where
the main street is obstructed, is (to adopt a vulgar
mode of expression) fortunately acquainted with
the routes through lanes and alleys. There are
on record, on the other hand, numerous dissections
[Seite 144] of females who died during the term of actual
menstruation, from which it was unequivocally
ascertained, that the catamenial discharge had
been wept out of, or discharged in a stillicidious
manner from, the uterine cavity of these subjects:
not to mention the arguments drawn a priori (as
metaphysicians express themselves), from which it
appears highly probable, that the end and desti-
nation of the menses are, to prepare the uterus
for a state of future pregnancy, and render it more
fit for the regular nutrition of the foetus. For
the very same reasons also this hemorrhagy ap-
pears to be attributed, with more propriety, to
the arterial than to the venous vessels of the
uterus.
With regard to the causes of this periodical and
perennial hemorrhagy, they are shrouded by so
thick a curtain of obscurity, and their investigation
is attended with such momentous difficulties, that
in the prosecution of this subject, we have not a
sufficient power of evidence to conduct us over
the arduous mound which divides the twilight-
region of probability from the more luminous realm
of demonstration, and certainty.
The proximate cause physiologists suppose to be
a certain topical congestion or plethora, to which
[Seite 145] opinion, indeed, the symptoms of the impending
catamenia, together with the profusion and nature
of the uterine blood-vessels fitly enough correspond,
and in favour of the truth of which they exhibit
a degree of testimony sufficiently respectable.
Among its remote causes it will be proper to
enumerate, the erect position of the body (a posi-
tion that serves as a characteristic distinction be-
tween the human species and most other descrip-
tions of animals); to which we must add, the
singular parenchyma of the uterus itself, and,
finally, the vita propria or specific life of that
important organ.
With regard to the cause of the periodical re-
currence of the catamenia, it will here be better,
much better to acknowledge our ignorance, than
to indulge ourselves in vague and visionary con-
jectures, and sportively range through the fair but
fallacious fields of mere speculative hypothesis.
For I am, indeed, persuaded, that all those peri-
odical phenomena which occur in the animal body,
whether in health or disease, (provided their in-
terval extend beyond the term of 24 hours) must
be ranked with those latent mysteries of animal
nature, which nothing but time, talents, and in-
dustry, will be ever able to develope.
Between the female mammae and
uterus (the former of which were, by the philo-
sopher Favorinus in his communications to Gellius,
elegantly and emphatically denominated, the sa-
cred fountains that nourish the human race, there
exists such an extremely potent sympathetic con-
nection, that these two organs may be said to be
indissolubly associated, or to accompany each other
hand in hand, in their phenomena and functions.
Thus, during the tender period of infancy, so
great is their imbecility and want of action, that
they are capable of performing scarcely any func-
tion at all: as the years of puberty advance,
they begin, at the same time, to acquire vigour
and activity, so that on the first eruption of the
catamenia, a swelling of the mammae or breasts
becomes also evident to the senses. Throughout
the subsequent periods of life those two organs
are either subjected to simultaneous and similar
changes, as when the breasts become turgid and
discharge milk during the progress of pregnancy;
or experience alternate and opposite affections,
[Seite 147] instances of which we have in the suspension of
the catamenia during the term of lactation, a more
copious effusion of the lochia when the secretion
of milk does not commence at the usual period,
&c. And, lastly, on the unwelcome accession of
old age, both the preceding functions fail at the
same time, so that when the catamenia finally
retreat, never again to return, the uterus and
mammae become equally flaccid, inert and wholly
incapable of their former action. A great variety
of pathological phenomena, easily observable in
cases of irregular menstruation, in fluor albus, and
other similar affections, shall be in silence preter-
mitted, although they furnish the most potent and
unequivocal testimony in confirmation of the
sympathy now under consideration, namely, that
which exists between the uterus and mammae.
Nor will this intimate sympathetic connection,
which subsists between the uterus and mammae,
appear in any measure extraordinary or surprising,
when we consider, that all those diversified sources
of physiological consent, particularly enumerated
on a former occasion (§ 54), jointly co-operate in
the establishment of such connection between these
organs of the female thorax and abdomen.
The anastomosis observable between the internal
mammary and epigastric arteries, was formerly
esteemed a circumstance of the highest importance
in the explication of the foregoing consent. Al-
though physiologists have hitherto attributed by
far too much to this remarkable anastomosis, yet
that it ought not to be entirely excepted from the
number of co-operating causes will appear ex-
tremely probable to any one who considers the
obvious and wide difference which exists between
the diameter of the epigastric artery in a state of
pregnancy, and that of the same vessel during the
period of lactation.
The two preceding organs, namely, the uterus
and mammae, possess also, in common with each
other, this further property, that they both retain
and exhibit a friendly affinity or attraction for the
chyle, by which means they solicit that fluid to
themselves, especially during the term of preg-
nancy, and thus convert it to peculiar uses.
The female mammae consists of a placentoid con-
geries of small conglomerate glands, distinguished
by numerous sulci into lobes of considerable mag-
nitude, and completely embedded in a mass of
[Seite 149] adipose substance. On the anterior part, in particu-
lar, a protuberance is formed by a more firm seba-
cious cushion, which is covered and protected by
a cutis of a very tender and delicate texture.
Each one of these lobes is composed of a num-
ber of inferior lobuli, and these again of what are
denominated acini or kernels, in which the incipi-
ent radicles of the lactiferous ducts originate, and
from the extreme ramuli or branches of the in-
ternal mammary artery extract a chyliform fluid,
which they are particularly destined to convey.
The fine filiform radicles uniting successively
in their onward passage, terminate finally in lead-
ing trunks, corresponding in number to the prin-
cipal lobes; so that they generally amount, in
each mamma, to about fifteen or perhaps a few
more. These trunks are frequently dilated into
more spacious sinuses, but never appear to be con-
nected by genuine anastomoses.
These trunks terminate in excretory canals of
exquisite delicacy and tenderness, which, being
collected and closely approximated towards the
centre of the mamma, form, by the co-operation
[Seite 150] of cellular membrane, the papilla or nipple. This
projecting papilla being interspersed and minutely
pervaded by an infinitude of blood-vessels and
nerves of extreme fineness and subtlety, is subject
to a very singular species of erection on the acces-
sion of certain external stimuli.
The nipple is surrounded by an areola or small
circle, which is conspicuous, as well as the pa-
pilla itself, on account of the singular colour of
the reticulum mucosum expanded immediately be-
neath the epidermis or cuticle. This areola is
further distinguished by small sebaceous follicles,
and like wise by a few minute lactiferous ducts with
which it is in some instances pervaded.
The human milk which is secreted in the glan-
dular organs hitherto described, is a fluid of a
well known colour, somewhat watery, and con-
taining also a small portion of oil: this liquid is
sweetish to the taste, extremely mild, and resem-
bles, in its general properties, the milk of do-
mestic animals belonging to the class mammalia,
except that it is not, like the latter, subject to co-
agulation from the action of acids, nor does it ex-
hibit, to the most attentive observation, the slight-
est vestige of volatile alkali.
When coagulated, however, by the influence
of spirits of wine, it exhibits the same component
elements of which the milk of those other animals
already mentioned is known to consist. For be-
sides the watery halitus which human milk emits
when recently drawn, and yet in a tepid state, its
serum, separating from the caseous or cheezy por-
tion, contains also the sugar of milk, which is
composed of the saccharine acid united to a calca-
reous earth, together with certain additional parts
oily and mucaginous in their natures. Lastly, it
contains also a cream or butter-like portion, the
globules of which are extremely various and
changeable in their magnitudes, thus vibrating in
their diameters from the 1/200th to the 1/600th part
of a line.
The analogy which is observed to exist between
chyle and blood, and between each of these
liquids and milk itself, renders it sufficiently pro-
bable, that this last humour, (which constitutes
at present the more immediate object of our con-
sideration), is a species of chyle renovated from
the volume of blood, or rather separated from this
crimson fluid (with which it had just formed a
junction) previously to its final and complete assi-
milation. This opinion, besides other arguments
[Seite 152] which might be advanced in its favour, derives
powerful testimony from the specific tastes of seve-
ral kinds of aliment being not unfrequently per-
ceptible in the milk of nurses; and also from the
chyle-like habit and constitution of that watery
milk, which not unfrequently exudes from the
breasts of females during the term of pregnancy,
and for a short time after the period of parturition.
The reason why, during the progressive con-
tinuance of lactation, this bland food of the
foetus becomes gradually more and more inspis-
sated, rich and oily, must be referred chiefly to
the lymphatic veins, with which the mammae
plentifully abound: Thus the more profuse the
afflux of milk, and the greater length of time this
afflux has continued, with the more power and
uniformity do these lymphatics absorb its serous
parts, and convey them back to the mass of cir-
culating blood, by which means they furnish the
most effective aid to the whole process of this se-
cretion (§ 476).
During the first days after parturition, a very
profuse secretion of milk occurs, and (provided
the mother lactates, i.e. suckles her child) is pro-
moted and kept up by the suction of the infant
[Seite 153] itself, until the catamenia return, which had for
a long time ceased to flow (§ 547). The exist-
ence of milk in the breasts of virgins truly invio-
late, in the breasts of new-born infants of each
sex, and even in the breasts of men themselves,
as well as in those of other male animals belong-
ing to the class mammalia, is a phenomenon which
not unfrequently presents itself to our observation.
A profuse quantity or accumulation of milk in
the breasts effectually solicits its own final excre-
tion, whence a spontaneous discharge of that fluid
is observed frequently to occur; this discharge
is further promoted by the external pressure of
the mammae, as well as by the suction of the
tender infant.
Having hitherto considered the
structure of the genital organs peculiarly belong-
ing to each sex, we come now to treat of those
functions or processes which constitute the imme-
diate end and destination of these organs, namely,
conception and the propagation of the human race.
In the order and progress of our enquiries into
these abstruse and interesting subjects, we will first
give a plain and simple narrative of the several
phenomena observable in this admirable and truly
divine process; and then attempt an investigation
of the energies from which these phenomena
appear to originate.
It is, in the first place, necessary to observe,
that the subjects of the human race have not, like
most other animals (all those, if I be not deceived,
belonging to the class mammalia, man alone ex-
cepted), any peculiar season of the year in which
they are unusually prone to venereal enjoyments,
[Seite 155] but are equally liable to experience, at every pe-
riod and under every varying temperature, the
gentle glow of love’s diffusive fires.
When therefore, the female of the human spe-
cies admits the embraces of the male, and while
they are thus mutually enwrapt in the ardour of
that animal instinct which far surpasses every other
both in the universality and the potency of its sway,
the uterus (if we be not greatly deceived) being
rendered turgid by a species of inflammatory or-
gasm, and animated at the same time by its own
specific life, (§ 538.) drinks in, as it were, the
seminal fluid emitted by the male, and effects a
synchronous discharge of that which is proper to
itself (§ 543); the fallopian tubes become at the
same time rigid, and with their simbricated extre-
mities embrace the adjacent ovaria: in one or the
other of these ovaria one of the vesiculae Graaffianae
is lacerated or burst, somewhat after the manner
of an abscess advanced to a state of complete ma-
turity, and the albuminoid liquid which this rup-
tured vesicula contained, being absorbed by the
orifice of the embracing tube, is thus conveyed
onward into the cavity of the uterus.
This liquid being discharged from the ovary,
the external lips of the small and recent wound
through which it was emitted, are again united
by a fine cicatrix, while the remaining delicate
vascular membrane in which the liquid had been
enclosed, constitutes what is called corpus luteum.
This body appears to be at first hollow and filled
with a quantity of plastic lymph, that in process
of time is converted into a fleshy nucleus, invested
by a firm cortex or membrane, which is inter-
spersed by a variety of minute, yet remarkable
blood-vessels.
The uterus being thus impregnated, the canal
leading through the cervex or neck of that organ,
especially towards its superior or internal orifice,
(§ 535.) is completely obstructed, in such a man-
ner, that according to the common course of
nature there is no room left for superfoetation.
The internal superfices of the uterus appears to
be invested with a slight inflammatory crust of
plastic or coagulable lymph, (§ 19.) which forms
the membrana caduca, (called also membrana de-
cidua). of Hunter.
This membrane-like crust physiologists distin-
guish into two laminae or layers; one of which,
denominated lamina crassa, invests the whole
internal cavity of the uterus, except the imme-
diate openings into the fallopian tubes, and the
internal orifice of the cervical canal; while the
other is the growth of a later period, and appears
to be generated in the following manner, viz.
after the formation of the ovulum is fairly com-
menced, and this minute body begins to strike its
roots into the decidua, already mentioned, this
second lamina begins gradually to expand, and is
thus continued from the place where those minute
roots begin to pullulate, over the remaining
superficies of the ovum, whence it has been
distinguished by the name of caduca reflexa.
Although the ovulum be formed itself at an
earlier period than the embryo which it is destined
to contain, yet the real organization of the former
seldom commences earlier than the termination of
the first week after conception. For I very much
doubt, whether or not, at an earlier period than
this, any unequivocal vestige of an organised body
has been ever observed in the impregnated uterus
of the human subject.
This ovulum, or little egg, is composed of two
proper membranes, besides that external adven-
titious covering, which it derives from the caduca
of Hunter.
The proper membranes are, first, an external
one, apparently destitute of blood-vessels, which
forms the chorion of modern writers. From the
earliest origin of this membrane a great part of its
external superficies is beautifully set with knot-like
flocculi or minute piles of inconceivable elegance,
from whence it has been called, chorion muscosum
seu frondosum, i.e. the moss-like, or leaf-like,
chorion. By means of those delicate piles, which
constitute the rudiments of the foetal part of the
future placenta, the ovulum is inserted (as if by
roots) into the decidua uterina. (§ 569.)
The other membrane, lying interiorly, is deno-
minated the amnion, which is also destitute of
blood-vessels, (§ 5.) it is indeed delicate and ten-
der, but yet of remarkable tenacity and strength.
For a few weeks after the first formation of the
ovulum, its two proper membranes differ very
widely from each other in point of size, the
chorion exhibiting the appearance of a larger
[Seite 159] bladder, to the inside of which the amnion
adheres under the form of a smaller one, and is
attached in particular to that part which is
opposite to the centre of the external floccose
superficies of the chorion.
The interstice which then exists between the
chorion and amnion is filled with a very subtle
chrystaline water, of doubtful origin, and transient
continuance.
For when the amnion begins, during the first
months after conception, to increase with greater
rapidity than the chorion, and to gain on the
latter membrane in point of magnitude, this chrys-
taline liquor must necessarily undergo a synchro-
nous, and perfectly correspondent, diminution.
The internal membrane of the ovum, from the
earliest period of its formation (§ 570), till the
final close of parturition itself, is constantly filled
with a fluid, denominated by physiologists, liquor
amnii. This liquid is aqueous, and of a pale
yellowish colour; it emits scarcely any odour, and
is to the taste bland, with a slight saline impreg-
nation hardly perceptible; physiologists generally
suppose it to be a source of nourishment, and
compare it to the white of an egg, from which it
[Seite 160] notwithstanding, differs in a very obvious and
essential manner, as may be easily demonstrated by
an attentive experimental investigation.
The sources of this fluid are as yet doubtful: It
is certainly, however, neither derived from the
foetus nor the umbilical cord, as it is not unfre-
quently found in abortive ovula, which contain
neither of these bodies.
The quantity of this fluid is in an inverse pro-
portion to the bulk of the foetus. Thus the
smaller and more tender the embryo, the more
profuse is the volume of liquor amnii, and vice
versa.
Hence we are at liberty to hazard a conjecture
respecting the primary use of this liquor, which
appears to be subservient, not so much to the
nutrition, as to the protection and defence of the
minute body of the tender embryo, as yet in a
gelatinous state, and, therefore, wholly unable to
bear the violence of external injuries. With
respect to that small portion of the liquor amnii,
which has been sometimes (though so rarely as to
deserve to be esteemed a preternatural occurrence)
found in the stomach of the foetus, it cannot
possibly be destined for the purpose of its nutrition,
as will be obvious to any one who considers how
[Seite 161] extremely inert and empty the chyliferous system
of even a more mature foetus appears, how unfit
for, and even how averse from, the arduous and
important process of chylification. To the forego-
ing circumstances we might (if necessary) subjoin
various examples of foetuses destitute of heads,
with diverse other arguments of a similar nature,
and tending to the establishment of a similar result.
The embryo itself, which (suspended by the
umbilical cord, as fruit appended to its foot-stalk),
floats in this liquor, begins to be formed about
the third week after conception: it appears first
under the very simple globe-like figure of a small
bean or kidney, to which the rudiments of the
extremities are gradually subjoined, the symmetry
and specific form farther completed, &c.
According to the usual course of nature, the
female of the human species is unipareus, and con-
ceives only one foetus at a time. She not unfre-
quentliy, however, bears twins, the proportion of
which to solitary births is, according to the calcu-
lations of Sussmilch, as one to seven. In a case
of twins each foetus has its own amnion, but they
are both enveloped in a common chorion.
That medium, by the aid of which a recipro-
cal intercourse is preserved between the embryo
and mother, are the umbilical cord, and the pla-
centa through which this cord is minutely dis-
tributed.
The umbilical cord, which appears to be co-
eval with the embryo itself, is indeed very strik-
ingly diversified, not only in point of length and
thickness, but also with respect to the place of
its insertion into the placenta, its varicose protu-
berances, &c. In general, however, it is formed
of the spiral contortions of three blood-vessels,
namely, a vein running to the liver of the foetus,
and two arteries which originate from the inter-
nal iliacs or hypogastrics. These vessels are se-
parated and distinguished from each other by cel-
lular partitions, running in various directions, and
have their lights or diameters frequently straitened
by the small nodes or valve-like bodies of Ho-
boken.
These vessels are collected and compacted to-
gether into a cord by means of cellular membrane,
which being filled with a singular and very limpid
humour, exhibits the appearance of jelly, but is in-
vested externally by a continuation of the amnion.
At the place where the foetus is attached to
this cord, the latter is joined by a peculiar body,
which originates from the bottom of the vesica
urinaria (§ 486.), and pursues a middle course
between the two umbilical arteries, namely, the
urachus. This body is, in the human species,
pervious, for at least a short space, and afterwards
totally disappears; but in other animals belong-
ing to the class mammalia, leads onward to what
is called the allantois. Of this allantois the human
foetus appears to be entirely destitute, unless we
be inclined to designate by this name that myste-
rious and transient vesicula umbilicalis, uniformly
observable in the human ovula, between the cho-
rion and amnion, which (if I be not greatly de-
ceived) Ifbr. de Diemerbroek first discovered long
before it was seen by Albinus or Zinn. But in
more modern times it is discovered too frequently,
and with too uniform an aspect in unvitiated and
fruitful human ovula, (even to so late a period as
the third month after conception), to be any
longer considered as an accidental, a morbid, or
a monstrous conformation of the part.
The blood-vessels of the cord, of which we
have already spoken, pass into the placenta, which
was formerly said to originate from the leaf-like
[Seite 164] superficies of the chorion, a membrane attached
to, and even inserted in, the decidua crassa:
Hence we perceive that the placenta is a body
composed of two different kinds of substance, re-
ceived from an equal number of sources. Thus,
for example, one kind called the uterine, from its
immediate apposition to that organ, is derived
from the decidua, and constitutes the spongy pa-
renchymatous portion of the placenta; while the
other belonging to the foetus, and therefore call-
ed the foetal part, is derived from the umbilical
vessels distributed throughout the chorion.
At this time the increase of the tender ovum
is unequal, so that the growth of the smooth por-
tion of the chorion is greater and more rapid
than that of the muscosum or moss-like; hence
it is evident, that the relative magnitude of the
placenta to that of the whole volume of the egg,
is greater in proportion as the conception is more
recent, and less, on the other hand, accordingly
as the period of parturition is nearer.
As pregnancy gradually advances, the placenta
becomes more and more close and compact in its
texture; it is impressed with grooves, and distin-
guished into lobes on its external surface which
respects the uterus, but is smooth and highly po-
lished on its internal, which, looking towards the
[Seite 165] foetus, is invested or lined by the amnios. With
regard to magnitude, thickness, figure, and situa-
tion or point of cohesion to the uterus, it is sub-
ject to a multitude of diversities; it is attached,
however, for the most part, to the fundus or bot-
tom of that organ; and is, upon the whole,
equally destitute of both sensibility (§ 205.) and
genuine irritability (§ 307).
Although all physiologists uniformly concur in
this, that the placenta is the principal organ
through the medium of which the tender foetus
is supplied with nutriment, yet various contro-
versies have latterly existed among them respect-
ing the genuine mode of its official action, and its
reciprocal relation, as well to the uterus as to the
foetus. From an attentive and impartial conside-
ration of all the testimony that can be collected
on this subject, the result appears to be, that there
exists no direct anastomosis between the blood-
vessels of the maternal uterus and those of the
umbilical cord; but the arterial blood which passes
by a continuous route from the uterus of the
mother to that portion of the placenta that owes
its origin to the decidua crassa, is there absorbed
by the incipient radicles of the umbilical veins,
that are distributed throughout the moss-like por-
tion of the chorion, and thus conducted into the
[Seite 166] venous trunk of the funis umbilicalis: while, on
the other hand, the blood which is conveyed
back from the foetus by the umbilical arteries,
being in like manner effused into the parenchyma
of the placenta, is taken up by the venous radi-
cles of its uterine portion, and thus finally re-con-
veyed into the substance of the uterus itself.
The foregoing opinions receive additional con-
firmation from the many well guarded but fruit-
less attempts that have been made by different
physiologists to inject the vessels of the umbilical
cord through those of the uterus, or, on the other
hand, to fill the vessels of the latter organ by in-
jections forced through those of the former. As
a further evidence in support of the same prin-
ciples, we may mention the difference which is
observed to exist between the pulse of the mother
and that of the foetus before their final disen-
gagement from each other; and lastly, it may
not be improper to add, as a circumstance tend-
ing to the establishment of the same result, the
observations which we formerly delivered respect-
ing the difference between the nature of the
foetal and that of the maternal blood (§ 147).
But further, it appears probable that a portion
of chyle is also conveyed to the foetus along with
the blood of the mother. For besides the conside-
[Seite 167] ration, that the blood of the mother is not at all
times equally pure and unmixed, but, for some
hours after every meal, carries along with it, in
an unassimilated state, that portion of chyle re-
cently received from the thoracic duct, it has
been demonstrated, on a former occasion, that the
uterus itself possesses a singular and strong affinity
to the chyle and milk (§ 550. 553.); and there
are also on record a great variety of observations,
from which it appears, that a milky juice has been
actually discovered in the uterine portion of the
placenta.
During the progressive advancement of preg-
nancy, while the foetus and secundines increase so
very remarkably in magnitude it is obvious that
the uterus must be also subjected to striking and
remarkable changes. Besides the augmentations
of its bulk, so extremely evident at first view,
these changes respect also its situation and figure,
but affect more especially the texture of this sin-
gular and important viscus. Thus, in consequence
of the uniform and weighty congestion of humours
which the gravid uterus is obliged to sustain, it
is likewise subjected to extreme alteration, both
with regard to the state of its blood-vessels, and
[Seite 168] also with respect to that of its parenchymatous
portion, throughout which those vessels are inter-
woven.
On the present occasion it may not be impro-
per to observe, that in proportion as the impreg-
nated uterus advances in magnitude, its blood-
vessels lose that mazy and convoluted appearance,
for which they are at other times so very remark-
able, and assume courses much more rectilineal or
direct; while at the same time they are subjected
to a considerable extension of their diameters, and
a consequent increase of their real capacities.
Thus, even the uterine veins have become so ex-
tremely capacious and prominent, as to have been
mistaken by numerous anatomists for true sinuses.
With regard to the parenchymatous portion of
the impregnated uterus, it becomes gradually
more and more lax and spongy, especially where
it is in contact with the ovum contained; so that
towards its fundus or bottom it becomes consider-
ably thick, and in a living and healthy female, is
greatly distended with blood, and possesses the
powers of life in a very high degree. This or-
gan is, notwithstanding, soft at the same time,
and very widely different in its general habit and
appearance from the firm and compact flesh of the
[Seite 169] uterus in an unimpregnated state: this difference
is still more striking if the subject containing the
gravid uterus be dead, in which case, provided
pregnancy be considerably advanced, this organ
falsely assumes in its texture (as was formerly well
observed by Arantius), a lamellated appearance.
It may not be amiss, on the present occasion,
briefly to enumerate a few more of the most
important changes to which the gravid uterus is
subjected, together with the most remarkable ones
that occur in the ovum and foetus. These changes
we will consider in the successive order in which
they appear throughout the series of ten lunar
months, which period of time is now, with suffi-
cient propriety, supposed to constitute the most
natural term of pregnancy.
As we uniformly observe the uterus beginning
to swell shortly after the time of impregnation,
(§ 567.) so being from that period increased both
in bulk and weight, it descends a little deeper into
the superior part of the vagina; notwithstanding
this descent it still retains its former figure in all,
except the following, respects, viz. its fundus
becomes a little more convex, its anterior paries
or wall, recedes a little farther from the posterior,
and its cavity, which was before very narrow and
[Seite 170] almost triangular, now accommodates itself to the
globose figure of the ovulum it encloses.
About the end of the first month the ovulum
itself amounts to the size of a pigeon’s egg, and
has the two deciduae separated from each other,
and also the small amnion situated at a distance
from the larger chorion: about the termination of
the third month it attains the size of a goose’s
egg, the caduca reflexa becomes approximated to
the crassa, and the amnion approaches nearer to
the chorion. The amnion abounds, at this time,
with a profuse volume of fluid denominated liquor
amnii. In this liquor the embryo, as yet very
tender, and extremely small in proportion to the
quantity of the surrounding fluid (being at this
time scarcely equal in magnitude to a small mouse)
appears to fluctuate in a loose and unsteady
manner, and is even now in a precipitate position.
About the fourth month after conception, the
uterus begins to assume more of an oval or some-
what globe-like appearance; its neck being more
and more softened, gradually shortened, and as it
were, destroyed, or rather latterly distended, it
again protrudes upwards, and begins to ascend
from the smaller into the larger pelvis. At the
same time the fallopian tubes themselves, with the
[Seite 171] convex bottom of the uterus being elevated or
borne upwards, are thus extended and elongated;
these tubes are, however, attached and connected
so closely to the sides of the uterus, that they
cannot recede from them, more than one half of
their own length; hence, when only viewed
superficially, they appear to originate and proceed
from the middle of the uterus, which has given
birth to a very erroneous opinion respecting the
astonishing increase of the fundus uteri.
From this time also the foetus acquires by
degrees such an increased magnitude, as renders
it more proportionate to the capacity of the ovum,
and begins about the same period to fix itself in a
more steady and firm position, which it preserves
till the very close of parturition: in this position
its head is placed in a downward direction, and
and its face turned towards the lumbar region of
the mother, inclining, for the most part, somewhat
obliquely towards the left side.
In the middle stage of pregnancy, which occurs
about the end of the fifth month, the uterus has
attained such a magnitude, that its fundus is
elevated to a point half-way between the pubes
and umbilicus, and the pregnant state becomes now
[Seite 172] observable from the external appearance of the
abdomen.
About the same time, the foetus becomes more
perceptible to the mother from the agitative mo-
tion of its body, though we are not able to deter-
mine, with accuracy and definitude the precise
period of time at which this motion takes place.
It appears now, however, to be more vigorous
and active, so that, according to the common use
and acceptation of speech, it may be said to be
the unequivocal action of life.
Throughout the sive remaining lunar months
the uterus, with the foetus which it contains, make
gradually still farther advancements in point of
magnitude. Thus, at the end of the sixth month
they reach nearly to the umbilicus or navel; and
about the termination of the eighth approach
even the scrobiculus cordis, in consequence of
farther protrusion upwards. The cervix uteri is
in the mean time more and more obliterated, re-
duced nearer to a level with the adjacent parts of
that organ, and its parietes or walls considerably
diminish in thickness.
Finally, about the end of the tenth month after
conception, the uterus being oppressed and over-
powered as it were, by its own bulk and weight,
(its longitudinal axis, amounting in general to 11,
and its transverse to 9 inches in length) begins
again to subside, and as the period of parturition
approaches, its ostium or mouth is gradually ex-
panded, and thus exhibits an orbicular or ring-like
opening.
Each membrana caduca, more especially the
reflected one, which adheres to the chorion,
having been gradually attenuated for several
months immediately preceding, exhibits now a
kind of net-like appearance distinctly marked by
short fibres of a whitish colour.
Such is the size of the placenta at this advanced
period, that its greatest diameter or breadth
amounts to about 9 inches, its least diameter or
thickness to about one inch; and its weight to
about one pound, and sometimes more.
The length of the umbilical cord for the most
part equals, and sometimes even exceeds, eighteen
inches.
The weight of a mature and well grown foetus
is nearly seven pounds, its length about twenty
inches.
The quantity of the liquor amnii is so extremely
variable, that it cannot possibly be ascertained
with any degree of definitude; in general, how-
ever, it scarcely amounts to a pound, provided the
foetus be healthy and robust.
Having thus enumerated and de-
scribed, in a plain and simple manner, the most
obvious and unequivocal phenomena of concep-
tions, together with such changes as are discovered
by attentive observation to succeed each other,
during the progressive course of pregnancy, not
only in the human ovum itself, but also in the
foetus which it embraces, and contains, we now
proceed to an investigation of those physical pow-
ers, by the influence and efficacy of which the
[Seite 175] sublime and truly astonishing process of generation
appears to be most probably accomplished.
There are not wanting certain characters of
high celebrity and distinction who attempt, even
in our own times, to explain the divine process, in
the following brief and summary manner; they
contend that the genuine work of actual generation
has not, at the present time, any real existence at
all; on the contrary, they allege, that the whole
human race possessed, under the form of original
germs, a joint pre-exstence in the genital system of
one or other of our first parents, and that these
germs have ever been, and are yet, subjected to
gradual evolutions, according as the progressive
lapse of time, aided by the co-operation of specific
causes, has contributed to awaken them to the
enjoyment of open and actual life.
Unfortunately, however, for the advocates of
the foregoing hypothesis, an essential difference
of opinion prevails among them on a point of
considerable magnitude and importance; thus,
while some of them are anxiously in quest of those
original germs among the animalculae that people
the semen of the male; others are searching for
those microscopic animals with no less industry and
zeal in the ovaria of the female.
To the latter of these sects in physiology, I must
acknowledge that I myself was formerly an adhe-
rent. I was lead to adopt the opinion of this
learned body not only by the respectable autho-
rity of its numerous advocates, but also by the
want of another more rational and satisfactory.
At present, however, I am obliged to repudiate
this doctrine entirely, to confess my errrors, and
endeavour if possible to correct them; having
been fully convinced, from a more close and mi-
nute attention to the phenomena of generation,
that nature performs this process in a manner quite
different from that contemplated and embraced in
the theory now under consideration.
For I am indeed daily more and more con-
vinced, that all living organized bodies possess,
from their earliest effort at organization to the
closing glass of their existence, a peculiar power
perpetually active, perpetually efficacious, the
immediate destination of which is, first, to mould
the bodies in which it resides into their native and
specific forms by the mysterious process of gene-
ration, to preserve them afterwards from destruc-
tion by the ceaseless function of nutrition, and, in
case of accidental mutilation, to restore their parts
again as far as consistent with the regular esta-
[Seite 177] blishments of nature, by the process of repro-
duction. That this energy may not be confounded
with the other kinds of vital energy, let it be
distinguished by the name of nisus formativus.
By this name, however, we mean to designate not
so much a cause as a perpetual and uniform effect,
the existence and reality of which are deduced
from actual observations made on the constant and
universal occurrence of certain physical pheno-
mena. It is thus, with views, and on principles
entirely similar, that we make use of the terms
attraction and gravitation, to denote certain ener-
gies or sources of action, the causes of which
are notwithstanding still involved in more than
cimmerian darkness.
To me it appears, indeed, highly probable, that
a stated period of time is requisite for accomplish-
ing the intimate mixture, the union and complete
concoction or maturity of those various inquiline
humours, belonging to each sex, (§ 518. 524.
542. 543.) which are doubtless discharged into
the cavity of the uterus, during every act of fruitful
coition. This term of preparation having at length
elapsed, and the liquors being fully matured and
brought into the most perfect state of union and
reciprocal influence, the nisus formativus is forth-
with excited into action, by means of which the
[Seite 178] spermatic mass, hitherto formless and chaotic, is
partly arranged and organized into the elegant
and beautiful envelopes of the nascent ovulum,
and partly moulded into the figure of the living
embryo which this minute bodie encloses. From
this theory we can assign a satisfactory reason,
why the uterus, for the two first weeks after con-
ception, appears to contain a mass of crude and
shapeless humours alone, and does not exhibit,
even to our best glasses (now brought to very
high perfection), the smallest vestige of an or-
ganized embryo, which, notwithstanding bursts
into view almost instantaneously about the end of
the third week, and is, even on its first appear-
ance, of considerable magnitude.
Of the nisus formativus we are presented with
more remote vestiges throughout every department
of natural bodies, not excluding even the most
simple elements of matter, where original germs
cannot possibly be supposed to have the shadow of
an existence. Thus, the clouds themselves assume
their own determinate forms, and even the stream-
ing torrents or veins of the electric fluid preserve
specific figures. There are, again, in the mineral
kingdom, specimens of metallic chrystallization,
which, if indeed the form alone be considered, and
[Seite 179] the prerogative of life kept entirely out of view,
bear the most striking resemblance to truly orga-
nized bodies.
In testimony of the truth of this, we need only
mention the curious hypniform crystals into which
refined or depurated copper shoots when first
reduced to a state of fusion, or that exquisitely
beautiful specimen of native peruvian silver which
they call silicinum or fern-like, from the resem-
blance of its figure to that of the plant denomi-
nated fern.
In like manner both the animal and vegetable
kingdoms afford numerous examples of organized
bodies, in which, from their magnitude being suf-
ficient to render them visible, from their beautiful
and unclouded transparency and from the extreme
rapidity of their progressive growth, the whole
process of generation is completely unmasked as it
were, and may be subjected to the examination of
the naked eye. The result of attentive and minute
observations made on this process in such subjects
as these, will be sufficient to evince, on the autho-
rity of the most indubitable testimony that, at least
in these bodies, no germs pre-exist. In illustration
of the above position it will be sufficient to mention
[Seite 180] from among the different individuals of the vege-
table kingdom, the conferra fontinalis. And from
those of the animal, the hydra viridis.
I should far exceed the limits prescribed to these
institutions were I to attempt a minute and circum-
stantial detail of the various arguments which, in
my view, nature herself furnishes to prove the
potent influence of the nisus formativus in the
process of generation. It may be proper, how-
ever, briefly to state a few of them, the force and
efficacy of which will appear sufficiently evident
oh the slightest examination.
The first argument I shall further propose on
this subject is taken from the history of those
curious and interesting subjects of organized nature
denominated hybrids. From a very beautiful and
celebrated experiment it appears, that, if prolific
female hybrids be successively through several
generations impregnated by males of any given
species different from the species of the females,
the new offspring will gradually deviate so widely
from the original form of the mother, and make
such evident and effectual strides towards that of
the father, as to lose at length every vestige of
similitude to the former, and become finally, (by a
[Seite 181] species of arbitrary metamorphosis) completely
assimilated to the external figure and appearance
of the latter.
There exists a phenomenon or fact relative to
the story and production of monsters, (the truth
of which is too well ascertained and established
to admit of a doubt), that merits our attention
while on the consideration of the present interest-
ing and intricate subject. It is a circumstance well
known to naturalists, that those animal produc-
tions denominated monsters (most of which, are
supposed, by the advocates for the celebrated
doctrine of evolution, to have pre-existed in a
monstrous germiform state from their original crea-
tion) – it is, I say, well known, that such preter-
natural productions, though very frequent among
certain species of animals in a subjugated or do-
mestic state (more especially among swine), are
notwithstanding very rarely found among the ori-
ginal and free-born animals of the very same spe-
cies, that have never been reduced to an humble
state of domestication, but still range the com-
mons and wilds of nature, wholly exempt from
the tyrannic controul of man.
It is necessary further to observe, that not only
monstrosities co-eval with the birth of animals,
but also subsequent adventitious mutilations and
other species of deformity, whether produced on
the animal system by accident or design, become
now and then completely hereditary; and thus,
what was at first the effect of art alone, may be
said to become at length the actual work of nature
herself.
The phenomena of re-production in general are
much more easily and rationally accounted for, by
considering them as the result of a nisus forma-
tivus, than by referring them to the pre-existence
of partial or local germs. This observation is
more fully and clearly illustrated, and its truth
more forcibly exhibited by an application of it to
some particular instances of re-production, as that
of the nails, for example, which after the entire
loss of the first, are well known to be frequently
regenerated on the second phalanx of the fingers.
Again, in certain parts of the body where no
pre-existence of germs can possibly be suspected,
we not unfrequently see organic parts of a pre-
[Seite 183] ternatural order produced by the vis medicatrix
naturae, when roused into action in consequence
of accidental diseases: As an example, and in
illustration of this, we may mention those small
ossifications known by the name of ossicula Wor-
miana, which, in cases of hydrocephalus internus,
are formed by the provident powers of the ani-
mal system, for the purpose of arching over and
thus completely closing the enlarged fontanel.
Finally, on comparing with candour, and weigh-
ing with impartiality, the various arguments on
each side of the question, it very evidently ap-
pears, that besides a power of exciting to motion
and action, which the advocates for the pre-ex-
istence of germs attribute to the male semen, in
order to render their favourite theory more spe-
cious and plausible, they must also bestow on that
fluid plastic or formative powers of the utmost
extent and influence: Whence it is obvious that
the doctrine for which they so zealously contend,
is of itself wholly inadequate to the explanation
of the numerous and intricate phenomena of ge-
neration, unless it be aided by the powerful con-
currence of a nisus formativus: Whereas, on the
other hand, the system which we have just pro-
posed on the subject is, without the bold pre-
sumption of pre-existent germs, fully sufficient to
explain all the multiplicity of phenomena attend-
[Seite 184] ant on this divine process. Let us then on the
present, as we should on every other point of con-
troversy, adhere to that doctrine which is most
simple in its nature, and most conclusive in its end,
from a thorough conviction, that an unnecessary
multiplication of entities or causes is no less repug-
nant to real and practical utility, than to the tenor
and spirit of sound philosophy.
The foetus being regularly formed and
fashioned by the energies of which we have hi-
therto treated, and advanced through the pro-
gressive stages of its subsequent growth, till it be
brought to a state of foetal perfection, must, after
arriving at this particular period of maturity, be
finally ushered into the enjoyment of light and en-
tire life, by the painful business of parturition.
This critical and important period arrives, agree-
ably to the usual order of spontaneous nature,
(which is the only object contemplated in physio-
[Seite 185] logy), about the termination of the tenth lunar
month, i.e. about the 39th or 40th week after
conception.
When a pregnant female finally arrives at this
eventful crisis, she is forcibly impelled to the la-
bour of parturition by an insuperable necessity,
already said (§ 295.) to be less subject to the con-
troul of the will than that which urges to the per-
formance of any other function belonging to the
human body.
With respect to the causes of a revolution so
determinate and sudden, different and even oppo-
site opinions have been entertained by different
physiologists. When we view, and take into at-
tentive consideration, all the attendant circum-
stances, it appears necessary to refer the cause,
which immediately impels to parturition, to an
eternal law of nature, which has hitherto received
no better explanation than has been given to a
great many other physical phenomena, which take
place in like manner at regular and stated periods;
such, for example, as the metamorphosis of insects,
the progressive stages of eruptive fevers, their
crises, &c. &c. Without subjecting themselves to
the just charge of fancifully entering on an absurd)
[Seite 186] speculation, certain physiologists have compared a
mature ovum, in the uterus of the human subject,
to the healthy fruit of vegetables, which when
completely ripened, fall spontaneously from their
parent plants, in consequence of a self-constriction
of the vessels through which their nourishment
was conveyed. It has been in like manner ob-
served, that as the period of parturition ap-
proaches, the human placenta suffers a slight de-
gree of constriction, and becomes thus prepared,
as it were, for its impending separation from the
surrounding uterus.
With regard to the opinion entertained on this
subject by physiologists in general, namely, that
the amazing expansion to which the impregnated
uterus is subjected, with a multitude of other im-
pressions or impulsive powers of a like nature, act
as the genuine exciting causes of parturition, it
appears to be very clearly and effectually invali-
dated by a great variety of arguments, which may
be fairly deduced from the unequivocal pheno-
mena of the animal economy itself: of these argu-
ments we think proper to mention the following,
namely, in numberless genuine cases of extra-
uterine conception, where the foetuses have been
contained, for example, in the Fallopian tubes, or
in the ovaria, the uterus has notwithstanding been
attacked by painful and convulsive throws, about
[Seite 187] the termination of the tenth lunar month after the
occurrence of such preternatural conception.
Besides the exciting, it is evident that there
must be also the joint co-operation of very pow-
erful efficient causes, arising from the nature and
properties of the uterus itself, and of the contents
which it encloses.
The proximate or immediate and primary cause
must be doubtless referred solely to the vita pro-
pria, or specific life of the uterus itself (§ 47.)
Of the remote causes the leading and most con-
siderable appear to be, the powerful efforts which
are made by the assistance of the process of respi-
ration, and the extensive consent or co-operation
of the intercostal nerve with the other portions
of the nervous system.
When finally the labour of genuine parturition
is excited, its phenomena observe a determinate
and regular order with regard to their commence-
ment and subsequent progressive course. In con-
sequence of this, they have been divided by ac-
coucheurs into different stages, of which four
have been enumerated by the latest writers on the
obstetric art.
In the first stage, the parturient patient expe-
riences a slight attack of those peculiar and well-
known pains, called in that state precursors or
warnings, which shoot in a direction from the
loins to the lower parts of the uterus, and which
are indeed felt at intervals, (though with dimi-
nished frequency and force), throughout the whole
period of parturition: the orifice of the uterus
begins, at the same time, to be considerably di-
lated, the abdominal tumor subsides, an inclina-
tion to pass urine becomes urgent and trouble-
some, and a copious discharge of mucus takes
place from the genital organs, now in a state of
distension and laxity.
In the second stage, the pains increase, and are
now distinguished by the name of preparantes, or
preparatory efforts: the inferior segment of the
coverings or membranes of the ovum are, at the
same time, protruded through the uterine orifice
into the vagina.
In the third stage the pains still continue greatly
augmented in their violence, and are now denomi-
nated dolores ad partum*. They act against the
[Seite 189] uterus with a more violent impetus, and thus
potently protrude it downwards, while, at the same
time the uterus presses with such astonishing force
on the encarcerated foetuss, as to occasion a rup-
ture in the membranes by which it is inclosed.
During the fourth and last stage of parturition,
while the patient is agitated with convulsive throws,
and tortured with the most excruciating pain, she
makes, at length, a violent exertion, (not un-
frequently accompanied with horripilation, grind-
ing of the teeth, trembling of the knees, &c.), by
the impulsive force of which, the head of the
emerging infant is urged forward, and finally pro-
truded quite through the external orifice with its
face foremost: in this unlooked for position it is
forced to advance, in consequence of the vertex
or crown of the head becoming lodged against the
arch of the pubes, while its other parts are urged
onward, and obliged to revolve on the stationary
vertex, as on an axis, or centre of motion. Thus,
amidst a profuse discharge of blood, the infant is
finally excluded from its place of confinement, and
introduced to the enjoyment of light and life.
The foetus being thus happily excluded, the
birth of the secundines succeeds, after a short in-
[Seite 190] terval, accompanied, in like manner, with painful,
though much less violent, throws: this latter birth
is, as well as the former, followed by a discharge
of blood, from that part of the uterine cavity to
which the placenta adheres by means of the
crassa or gross membrana decidua.
The uterus, being thus, at once delivered of
its two-fold birth, by which it had been encum-
bered and oppressed, is now contracted by little
and little, till it is finally restored to its former
figure, and reduced almost to its former size.
During the first week after the birth of the
child, there exists, from the genital organs of the
mother, an uninterrupted effusion of the lochia,
a discharge very much resembling the catamenia,
except that it is more profuse in quantity, espe-
cially when not in any measure checked or dimi-
nished, by the commencement of lactation. The
bloody or florid colour of the liquid discharged by
this evacuation is, notwithstanding, changed about
the fourth day to a pale red, and from thence
passes on to assume a white appearance.
As soon as the uterus is thoroughly cleansed
of all remaining fragments of its deciduous mem-
[Seite 191] brane, and has thus finally completed the painful
and tedious task of propagation, it may again
resume the natural process of menstruation, or
even return to the performance of fresh immola-
tions on the altar of conception itself.
From what has been already said
respecting the mode of life enjoyed by the foetus,
while yet encarcerated within the parietes, and
immersed in the warm-bath of the maternal uterus,
it is extremely obvious that an immense difference
must; exist, between the functions of the animal
economy in this state, and that which shortly suc-
ceeds, when the infant is finally introduced, by
birth, into entire life, and is possessed of a power
of spontaneous motion. An enumeration and
statement of the leading points or circumstances
of this difference, constitutes the design of the
present section.
To begin then with the circulation of the blood,
it must be observed, that the route of this crimson
fluid is different in the foetal state, from what it is
in that which immediately succeeds paturition or
birth. During the continuance of the former
state, the foetus is connected, and preserves a cir-
cular intercourse with the uterine placenta, by
means of the umbilical cord; it has never, as yet,
inspired air for the purpose of supplying the blood
with that vital pabulum, a process which immedi-
ately commences and is uniformly continued after
birth, when this reciprocal connection between
the mother and child, is finally destroyed.
The umbilical vein originating from the placenta
of the mother, and passing through what is called
the umbilical ring of the foetus, directs its course
towards the liver, where it discharges its blood
into the sinus of the vena portarum; from thence
the blood is distributed in part, by the ramifica-
tions of this memorable vein, throughout the liver,
and in part, conveyed by a direct route through
the ductus venosus Arantii, to the inferior or
ascending vena cava.
The two foregoing canals, namely, both that
portion of the umbilical cord which is contained
[Seite 193] in the abdomen of the foetus, and also the ductus
venosus mentioned above, suffer after birth an
entire obliteration of their cavities, and assume the
nature and appearance of solid cords, insomuch
that the former constitutes what is denominated
the round ligament of the liver.
When, in the foetus, the blood is conveyed
from the inferior vena cava to the right side of the
heart, the greater part of it is denied a passage
from thence through the lungs, and is therefore
directed towards the left or posterior auricle of
the heart, by the valve of Eustachius, and admit-
ted into that cavity through the foramen ovale.
For over the mouth of the inferior vena cava,
after its ascent from the cavity of the abdomen in
the foetal state, a valve of alunated figure is extended,
which, in honour of its immortal discoverer, has
been called the valve of Eustachius. This luni-
form body is, for the most part, gradually oblite-
rated as life advances, although in the foetal state it
appears to perform the important office of directing
the blood, emerging from the abdominal cavity,
towards an orifice to be spoken of presently, which
penetrates the septum situated between the two
auricles of the heart.
The orifice referred to in the preceding para-
graph is called the foramen ovale, through which
by far the greater part of the ascending column of
blood, derived immediately from the inferior vena
cava, is conduced into the left auris of the heart
during each diastole of the auricles: of this blood
the regurgitation is effectually prevented, by the
elegant falciform valve formerly mentioned, which
is closely spread over the foramen, and appears to
close that orifice completely, during each systolic
motion of the auricles. During the first years of
infancy the foramen ovale is in part closed by means
of this small valve, and partly obliterated by the
gradual but slow adhesion of its sides: in cor-
respondence to such adhesion, the valve of Eusta-
chius itself undergoes also a slow and gradual
diminution in point of size, till scarcely a wreck of
it is, left behind.
Of that blood which, at the same time, enters
the right auricle of the heart from the superior
vena cava, a very small portion only can be received
by the lungs of the foetus, as yet in a weak and in-
active condition: it is therefore taken up by the
ductus arteriosus, from the trunk of the pulmonary
artery (of which this duct is indeed the leading
branch) and conveyed by a direct and speedy route
[Seite 195] to the arch of the aorta, without passing through
the lungs at all. Within the course of a few weeks
after the birth of the infant, the cavity of the
ductus arteriosus is, for the most part obliterated,
and its parietes or walls converted into the nature
and appearance of a dense and firm ligament.
The blood being propelled through the trunk
of the aorta, that portion of it, destined to be
re-conveyed to the system of the mother, enters
the umbilical arteries (§ 578.) which pass through
the annulus umbilicalis, on each side of the urachus,
and are, in like manner, after the birth of the
infant, converted into solid imperforated cords.
As the lungs perform in the foetus scarcely any
function at all, their general habit and appearance
differ very materially from those which they assume
after the infant has commenced the process of
respiration. Thus, their bulk is proportionally
much less, their colour more dark, their substance
more compact, and hence their specific gravity so
much greater, that when immersed, recent and
free from putrefaction, into a vessel of water, they
sink instantly to the bottom; whereas, on the
other hand, if the infant has been born in a living
state, and taken in air by inspiration, these viscera,
[Seite 196] for the most part, float on the surface of water, or
of any other fluid equally ponderous. The right
lobe of the lungs appears to possess the peculiar
prerogative of being dilated a little sooner than
the, left by the incipient influx of air in the first act
of inspiration. With regard to the other pheno-
mena of this new function of life, they were
enumerated formerly, when we were treating
particularly of the process of respiration.
From the observations which were formerly
proposed on the nutrition of the foetus (§ 574,
581.), it may be very easily perceived that the
state and condition of the alimentary tube and chy-
lopoietic system, are extremely different before,
from what they are after, the birth of the infant,
these viscera being in the first case inert and
wholly incapable of action. Thus, for instance,
in the tender embryo of only a very few months
existence, the larger, are perfectly similar in habit
and appearance to the smaller, intestines; but
during the closing months of pregnancy the former
portion of the intestinal canal (being considerably
distended with meconium) appears to merit unequi-
vocally that name by which it is afterwards dis-
tinguished from the latter.
The meconium is a peculiar species of saburra,
of a green colour, shaded with more or less of a
brownish cast. It is doubtless derived from the
inquiline humours of the foetus itself, more espe-
cially from the bile: that it is indeed of a bilious
origin we are induced to believe from the follow-
ing considerations: – First, because the earliest
appearance of this excrementious substance corres-
ponds exactly, in point of time, with the com-
mencement of the biliary secretion; and, Secondly,
because we learn from accurate observation, that
such monsters as are destitute of a liver, have their
intestines supplied with nothing else but a small
quantity of colourless mucus instead of the more
common and natural meconium.
In the new-born infant the form of the coecum
is also very widely different from what it is in the
future periods of life; and this intestine is then
continued in a direct line with the appendicula
vermiformis.
Several other differences and peculiarities, of a
similar nature, we have already spoken of on parti-
cular occasions, and shall here, therefore, only
[Seite 198] glance on them in the most brief and transient
manner:
They are the Urachus (§ 579.) the membrana
pupillaris (§ 259.) and, in the male foetus, the
descent of the testes (§ 501.)
A few additional peculiarities will be spoken of
with more propriety in the following section.
Others, as being of less importance, we volun-
tarily pretermit in perfect silence.
The present appears to be indeed a very fit
and favourable opportunity for calling the attention
of the reader to three parts of the human body,
altogether peculiar in their nature and obscure in
their destination, which are of a greater propor-
tional size in the foetus than in the adult, and
appear to be in a special manner subservient to
the economy of the former. The true and une-
quivocal uses of the parts now in contemplation
have not as yet, however, been clearly and satis-
factorily ascertained, although, anxiously sought
after by the combined labours of numerous and
very respectable anatomists. These parts are
designated by the name of glands, although their
parenchyma is far, very far, different from the
glandular, and they have never been discovered
[Seite 199] to possess the faintest vestige of an excretory duct.
They are denominated the thyroid gland, the
thymus, and the renes succenturiatati.
The thyroid gland is situated on the anterior
side of a cartilage of the same name, which enters
into the conformation of the larynx. It consists
of two lobes, and is of a lunated or falciform
figure; in the foetus it is distended with a lympha-
tic fluid, but, as life advances, becomes gradually
more and more spoliated of its distending liquid.
The thymus consists of a mass of shining and
very tender flesh, is, in like manner with the pre-
ceding substance, bilobular, now and then divided
into two distinct portions, and contains also occa-
sionally a cavity of considerable dimensions. This
body is situated beneath the middle and upper
part of the sternum, and ascends on each side even
to the throat itself; in the foetus it is large,
irregular in its figure, and abounds with a juice of
a milk-like nature; but as youth advances it gra-
dually diminishes in size, until, finally, on the
accession of old age, it is so completely obliterated
as to exhibit scarcely a shadow of its former
existence.
Lastly, The Renes succenturiatali, (called like-
wise glandules suprarenales, capsulae atrabiliariae,
&c.) are situated beneath the diaphragm, resting
on the upper extremities of the kidneys. In adults
they are not only diminished in size, but are also
removed to a small distance from the contact of
the kidneys, and contain a dark coloured fluid,
which in the foetus is more inclined to a pale red.
Having hitherto minutely considered
the human economy, in detail, agreeably to the
several classes into which its physical functions are
divided, nothing further remains at present than
to take a general, brief, and comprehensive survey
of man in his transit over the diversified stage of
life, and thus accompany him, from his earliest
vital pulse in an embriotic state, throughout the
[Seite 201] leading revolutions and aeras in his economy, down
to the final termination of his existence.
First, then, about the third week after concep-
tion, the rudimental organization of the embryo
appears to take place (§ 575.): about the fourth
week afterwards, while the embryo still enjoys an
extremely low and languid degree of life, border-
ing even on that of a vegetable, it is supplied with
the first portion of genuine red blood (§ 13.)
The motion of the corculum or minute heart, has
been but very seldom observed by physiologists in
the incipient human embryo, but was long since
discovered by Aristotle in the incubated chick, and
has been, from that period, designated by the
name of the punctum saliens.
About the seventh or eighth week after con-
ception, the momentous process of osteogeny, or
the generation of bone, commences in the human
subject. Those parts where osseous, or bony
matter makes the first depositions for the formation
of its nuclei, are the clavicles, the ribs, the verte-
brae, the long cylindrical bones of the extremities,
the mandible or lower jaw, and certain other
bones of the face, &c. Those parts again where
the osseous depositions are secondary in point of
[Seite 202] time, are some of the plain bones of the skull,
such, for example, as the frontal and occipital: –
while the bones of the neck, &c. are formed at a
still later period.
The younger the embryo is, in particular, or to
proceed on a more extensive and general scale,
the younger the human subject is, whether before
or after birth, with the greater rapidity does its
growth advance, and vice versa.
About the middle period of pregnancy, the
foetus becomes what may be called a genuine sub-
ject of vitality or life, agreeably to the rule of
discrimination laid down on that particular point in
a former part of this work (§ 585.) About the
same time, the secretion of certain humours make
their first appearance, such, for example, as the
fat (§ 38) and the bile.
As the foetus advances towards maturity the
tender hair begins to pullulate, the nails emerge
into view, the membrana pupillaris gives way
(§ 260), and in the male sex the testes begin to
descend (§ 505).
About the close of the tenth lunar month, the
infant is finally released from its imprisonment by
means of parturition (§ 603); after which, besides
the astonishing revolutions in almost the whole
economy of its system, detailed more amply and
minutely above, it is also subjected to various
changes in its external habit and appearance;
thus, for instance, that delicate lanuginous hair,
with which the face of the new-born infant is
overspread, disappears by degrees, its wrinkles are
gradually obliterated, its anus retires within the
nates, which now begin to be slowly protruded,
&c. &c. &c.
The infant also learns, (though indeed by very
slow degrees), the exercise of the various faculties
of the mind, such, for example, as those of per-
ception, of attention, of reminiscence, of desiring,
&c. &c. from whence, in a very few months after
birth, it is subjected to dreams, &c.
The organs of the external senses undergo also
gradual or progressive improvements, and are
advanced to still higher and higher degrees of
perfection, such as the external ears, the internal
[Seite 204] nares, also the coverings of the eyes, such as
their supra-orbital arches, their supercilia, &c.
The bones of the cranium acquire, in the mean
time, an augmented degree of firmness. The
fonticuli or chasms between the different bones
are gradually arched over, and about the eighth
month the process of dentition commences.
The infant is now ready to undergo ablactation
or weaning, being furnished with teeth for the
express purpose of subduing more solid food, and
not to injure the papilla, or nipple of the mother.
About the close of the first year, the infant
learns to stand alone, and support itself in an erect
position, the greatest and most enviable prerogative
with which the human body is dignified.
The infant being thus removed from its mother’s
breast, and possessing the use and command of its
feet, makes daily advances in growth, and im-
proves in the power of spontaneous motion, while
it acquires, at the same time, another very import-
ant privilege conferred on the human race, namely,
the use of speech. Ideas which have become
[Seite 205] familiar to its mind it now begins to make attempts
to express by the aid of that important organ the
tongue.
About the seventh year of life, the milk-teeth,
or first set, being twenty in number, drop out by
degrees, and are replaced in a series of years by
a second dentition, consisting of thirty-two peren-
nial or permanent teeth.
During this period of infancy the memory far
surpasses in strength and perfection the other pow-
ers of the mind, and appears to be indeed in a
very peculiar manner adapted for receiving and
retaining the signs of things; whereas after the,
fifteenth year of life, the glowing powers of the
imagination usually gain the ascendency.
This superior strength and activity of the ima-
gination very happily manifests itself throughout
those years of life in which the human subject is,
by a variety of striking and very important
changes in the body, gradually prepared for the
future performance of such functions as constitute
the characteristic distinctions between the two
sexes.
Shortly after this period the mammae or breasts
of the female subject begin to swell, the chin of
the male becomes clothed in a mantle of coarser
down, and a variety of other phenomenon occur
in each sex, which serve in like manner to an-
nounce the gradual approach of puberty: thus,
in the female the catamenia begin to flow; while
in the male the secretion of a true semen com-
mences, which is uniformly accompanied by a
more luxuriant crop of beard, and a very striking
change in the voice from a shriller to a graver
tone.
About the same time the sexual instinct (§ 289.)
that spontaneous and potent call of nature, is first
awakened into action, and man, now in the blos-
som of life, is fitted and inclined to venereal en-
joyments.
The crisis or precise period of puberty cannot
by any means be accurately ascertained. It is
much varied by diversities of climate and of tem-
perament. In general, however, it occurs earlier
in the female than in the male sex; thus, in our
climate females may be said to have arrived at
this interesting period against the fifteenth, but
males not before the twentieth year of life.
Shortly after the above period the human body
finally ceases to increase in stature; this particular
is also influenced and greatly diversified by differ-
ence of climate, not to mention the countless va-
rieties that are exhibited relative to this point,
not only by different individuals, but even by
whole families.
About this period also the epiphyses, which had
been hitherto distinguished from the bones to
which they were attached by very visible lines of
separation, become so intimately united to, and so
completely coalesce with these bones, that not a
vestige is left to serve as a memento of their for-
mer diffusion.
With respect to the term of perfect manhood,
which constitutes indeed the most lengthy, as well
as most useful and important period of human
life, we find it characterised by the highest de-
grees of vigour and uniformity, when we examine
the functions of the body, and by that most inva-
luable prerogative, maturity of judgment, when
we take into consideration the faculties of the
mind. Throughout this interesting period the
[Seite 208] lamp of human life blazes with the highest degree
of intensity and splendor.
The heralds which unerringly announce the in-
trusive approach of old age are, in females, the
cessation of the catamenia, (§ 547.), in males, a
languid propensity to venereal gratifications, and
in both an invasion of what is called the rigidity
or dryness of old age, with a slow but sensible de-
clination of the vis vitae, or aggregate power of
performing the various functions of life.
Finally, the frigid reign of the ultimate degree
of old age is strongly characterised by the follow-
ing concomitant phenomena, namely, a sluggish-
ness and increasing dulness of the senses, both ex-
ternal and internal, an irresistible call for longer
indulgence in sleep, and a torpidity and languor
in all the functions of the animal economy. The
hairs assume a silvery gray, and fall in part from
their exalted situation. The teeth themselves
drop spontaneously from their declining sockets.
The neck is no longer able to support the head,
nor the tottering legs to sustain the weight of the
incumbent body. Even the bones themselves,
those indispensible sulcra of the whole machine,
[Seite 209] are obliged to bear a part in this irremediable
and universal decay.
We have thus arrived at length to the remote
ultimatum of physiology, namely, death without
disease, or the euthanasia of old age. To conduct
and protract human life to this only natural ter-
mination (the causes of which are sufficiently ob-
vious from what has been already laid down) con-
stitutes indeed the alpha and omega, i.e. the sole
and exclusive end and object of the healing art.
The phenomena of this natural death (as observed
in man when about to resign himself to its potent
grasp), are, a coldness of the extremities, a loss
of the brilliancy of the eyes, a very small and
slow pulse, accompanied with intermissions pro-
gressively increasing in frequency, and lastly a slow
respiration, which by a more forcible act of ex-
spiration, is at length closed for ever.
In the live-dissections of animals belonging to
the class mammalia, there is a convenient oppor-
tunity for observing the last exertions of the heart,
from which it appears, that the right ventricle
and auricle of that viscus resist the encroachments
[Seite 210] of death longer, and continue the motions of life
to a later period, than the left.
Coldness accompanied by rigidity, a cadaverous
stench, but more especially a flaccidity of the cor-
nea, and a hiatus or gaping of the anus ascertain
in the most unequivocal manner the complete death
of the body. When in the corpse an aggregate
collection of all these signs occur at once, not even
the sceptical Pliny himself could find room to inter-
pose the shadow of a doubt respecting the complete
extinction of animal life.
To ascertain with definitude the natural term of
the life of man, (or to point out that period
which may be considered as the more frequent and
regular goal or ne plus ultra of human existence),
is, indeed, a matter attended with the utmost diffi-
culty. I have notwithstanding learnt, from exa-
mining with care and comparing with accuracy, a
great number of bills of mortality, that a consider-
able proportion of such Europeans as are advanced
in years reach, but that very few of them pass,
the eightieth and fourth year of life.
We may observe upon the whole, that in con-
sequence of the weakness and tender susceptibility
of infancy and childhood, the intemperance and
irregularity of an infinitude of adults, the incon-
trolable violence of diseases, and a countless
multitude of fatal casualties, not more of mankind
than seventy eight in a thousand resign their lives
to that species of death now under consideration,
namely, death without disease. Notwithstanding
the truth and authenticity of the preceding obser-
vation, yet on making a genuine estimate of human
longevity and comparing it, under similar circum-
stances, with that of the other subjects belonging
to the class mammalia, whose natural term of
existence is known to us, it will evidently appear,
that, except the baseless declamations of sophists
regarding the miseries of human life, nothing can
be more unfounded and irrational than their splen-
did and verbose effusions respecting its brevity.
in which is exhibited a
Condensed and Summary View
of the
EXISTING DISCOVERIES AND SPECULATIONS
Relative to the Subject of, what is usually denominated,
ANIMAL ELECTRICITY.
Steady and uniform as the lapse of
time itself, are the exertions made by the enter-
prize and industry of man, to shed light on the
arcana or secret processes of nature. In proportion
as such laudable attempts are prosecuted with
boldness and crowned with success, revolutions and
improvements take place in the various branches
of physical science. Revolutions derive birth from
the detection of error, while improvements result
from the discovery of truth. On the repudiation
of false principles in science, as well as on the
developement of new ones deduced from the reci-
[Seite 214] procal concurrence of numerous and unequivocal
facts, it is not without the sanction of reason and
propriety that new systems are forthwith compiled,
digested and ushered into the world.
For, to be complete and satisfactory, a system
in any branch of science, should embrace and ar-
range in order all the well authenticated principles
spontaneously resulting from facts already ascer-
tained and observations already made, relative to
that particular branch. A system less general and
comprehensive in its scope than this, should be
deemed, at best, but defective and partial, and
received as the abortive production of a mind
deficient in point of information.
Of the former description was the famous phy-
siological system of Baron Haller, at the time its
illustrious author first submitted it to the eye of the
world. That excellent physician and philosopher
grasped in his acute and comprehensive mind, and
detailed at large, in the work to which I here
allude, all the authentic and well defined princi-
ples resulting from the infinitude of facts with
which the science of physiology was at that time
enriched.
But all systems are stationary and have been as
yet imperfect, while, happily for the interest of
[Seite 215] man, improvements in science are progressive and
advancing towards perfection. In the course of a
few years, such a blaze of physical light was dif-
fussed abroad by the industry and ingenuity of
philosophers in general, but of physicians and
chemists in particular, that the deficiencies and
errors of the Baron’s elaborate system were ren-
dered obvious to the most weak and inattentive
observer. In the important doctrines respecting
the causes of animal heat and the nature and
purposes of respiration, in particular, entire revolu-
tions were effected by the numerous and ingenious
discoveries of chemists in that branch of science
denominated aerology.
To supply, as far as possible, the deficiencies
of this system of Haller, and to circumvent the
errors which the authority of so celebrated a cha-
racter might tend to diffuse throughout the minds
of his numerous readers, became desiderata of no
small moment in the science of physiology.
The most effectual method of accomplishing these
desirable ends was too obvious to escape discovery.
For as violence is most effectually repelled by
counter violence, and one disease not unfrequently
removed from the animal system by the impetuous
invasion of another, so in like manner, in science,
the defects of one system are most advantageously
[Seite 216] supplied, and its errors most effectually contro-
verted and exposed, by the plenitude and unequi-
vocal certainty of the principles of a rival system.
This truth did not escape the observation of that
learned and acute professor, of Goettingen, who
now fills the chair which was formerly rendered
vocal by the eloquence of the immortal Haller.
Need I add, that professor Blumenbach is the man
to whom I allude – a man, for the completion of
whose greatness and utility in physical science,
nature and art appear to have all but exhausted
their abundant resources! For industry and perse-
verance in the collection of materials, for powers
to combine and arrange materials when thus col-
lected, and for ingenuity and acumen to deduce
and speculate from such combination and arrange-
ment, the present age certainly boasts few – too
few physiologists who may be set in competition
with the illustrious Blumenbach.
For this physician and philosopher was reserved
the honourable and important talk of collecting,
digesting and consigning to publicity, a system of
physiology destined to supply the deficiencies and
correct the errors of that which had already
resulted from the labours of his celebrated friend
and predecessor. The system of professor Blumen-
bach was, like that of Baron Haller, perfect and
[Seite 217] complete at the time in which it was handed to
the world. There existed not, at that period, an
established principle, nor scarcely even a probable
conjecture in physiology, with which he was not
minutely acquainted, and which he did not draw
into the extensive and powerful vortex of his
system.
Had the science of physiology been finally com-
plete at the time in which professor Blumenbach
wrote, the industry, the immense resources and
the comprehensive talents of that philosopher
would, no doubt, have quite precluded the neces-
sity of future systems in this branch of science.
But in the unfathomed depths of the animal
economy more arcana yet existed – more terra
incognita lay yet unexplored, and further re-
searches of enterprise were therefore essential.
By the combined labours of experimental physi-
ologists in different parts of the world, this branch
of science was at length matured for giving birth
to another discovery, which will probably be found
of equal importance, in explaining the phenomena,
and in removing the diseases of the animal system,
with that which consigned to immortality the name
of the illustrious Harvey. The discovery to which
I wish at present to direct the attention of the
reader is that of, what is usually called animal
[Seite 218] electricity, or, of the existence and operation of a
fluid extremely similar to electricity in the living
animal system. For the fortunate Galvani pro-
fessor of anatomy at Bologna, was reserved the
honour of lighting by accident on this beautiful
and divine discovery – a discovery which entitles
its author to be ranked with the great promoters
science and the essential benefactors of man.
That such a fluid did actually exist in the bo-
dies of animals, had been long suspected by phy-
siologists and other speculative philosophers. The
matter rested however on pure conjecture alone,
and was yet unsanctioned by the tests of experi-
ment and observation. The apparent intricacy
of the subject depressed the hopes of the boldest
experimenters, and the subtlety of the investiga-
tion seemed to throw an insurmountable bar in the
road to success. But accident not unfrequently
does more for the real advancement of science,
than boasted genius and industry are able to ac-
complish. It was accident that first suggested to
the celebrated Gallileo the construction and use
of that optical instrument denominated the tele-
scope – It was accident which first led the immortal
Newton to the original conception of that prin-
ciple of gravitation, by which he afterwards ex-
plained, with such facility, the movements and ex-
quisite balance of the material universe. And it
[Seite 219] was, in like manner, accident – fortunate accident,
that first suggested to the industrious and acute
Galvani the mode of experimenting, with effect,
on the intricate subject of animal electricity – a
subject which may possibly be destined as the only
proper clue to conduct future physiologists to the
genuine springs and principles of life itself.
‘“Whilst the professor (alluding to Galvani)
was engaged in dissecting a frog in a room where
some of his friends were amusing themselves with
an electrical machine, one of them drew a spark
from the conductor, at the same time that the
professor touched one of the nerves of the animal,
in an instant the whole body of the frog was
shook by a violent convulsion. The professor
was astonished at the phenomenon, and believed
it owing to his having wounded the nerve; to
allure himself whether this was really the case,
he pricked it with the point of his knife, without
any motion of the body being produced; he now
touched the nerve with the instrument as at first,
and ordered a spark to be taken from the machine,
on which the contractions were renewed. The
experiment was repeated a third time, but the
animal remained motionless; however, upon per-
ceiving he held his scalpel by the handle, which
was of ivory (a bad conductor), he changed it
[Seite 220] for a metallic one, and re-excited the movements,
which he constantly failed of doing whilst using
an electric substance.’
‘After having made a number of experiments
with the electrical machine, he resolved to prose-
cute the subject with atmospheric electricity. To
this end he raised a conductor upon the roof of
his house, from which he brought an iron wire
into his room, and to this attached metal con-
ductors, connected with the nerves of the animals
destined to be the subjects of his experiments,
and to their legs he tied wires, which reached the
floor. Considerable movements were observed in
the animals, whether of cold or warm blood,
whenever it lightened. These preceded thun-
der, and corresponded with its intensity and re-
petition, and even when it did not lighten the
movements took place when any stormy cloud
passed over the apparatus.”’
‘“Professor Galvani one day suspended some
frogs, perhaps with similar views, on metal hooks,
fixed in the spine of the back, upon the iron rail-
ing of his garden; several times he remarked that
these animals contracted, and appeared to receive
shocks; at first he conceived the movements were
owing to changes in the atmosphere, but a more
[Seite 221] scrupulous examination undeceived him. Having
placed a prepared frog* upon an iron plate in his
room, and happening with his dissecting forceps to
press it against the plate, he observed the move-
ments to take place. This experiment succeeded
with all metallic bodies, but more particularly well
with silver; non-conducting substances were not
proper for it. From this period our author began
to suspect the animal possessed an electricity of its
own; and in this suspicion he was further con-
firmed by the following circumstance: – He held
[Seite 222] a prepared frog by a hook with one hand, so as
to let its feet rest upon the bottom of a small sil-
ver cup, which he happened unintentionally to
strike with the other; at the instant the body of
the animal fell into violent convulsions. If one
person held the prepared frog, and another touch-
ed the cup, no movements were excited. The
professor being now aware of the necessity of a
communication, undertook a series of experiments
for the farther investigation of this subject. He
first placed a prepared frog upon a non-conduct-
ing surface, and brought one end of a conductor
in contact with the hook which secured the ani-
mal, and with the other touched its feet, on which
the contractions took place. When the conduct-
ing arch was interrupted by a non-conducting
substance, the frog remained motionless, &c.”’
No sooner had professor Galvani published to
the world his experiments on animal electricity,
than their fame dispread, swift us the intangible
fluid which they regarded, throughout the differ-
ent parts of Europe. Animal electricity became,
in a short time, a subject of very interesting specu-
lation to medical philosophers. Among the seve-
ral physiologists who entered the lists in this in-
vestigation, the most distinguished whose writings
have fallen into my hands, are Dr. Valli, an Italian
physician, from whose publication the preceding
[Seite 223] account respecting the first discoveries of Galvani
is extracted, and Mr. Fowler, a native of the
island of Great Britain.
Doctor Valli appears to have led the van of
those philosophical characters who first co-ope-
rated with the celebrated Galvani in investigating
that animal fluid, the existence of which had been
so long suspected, but so lately realised by actual
experiment. After repeating most of the experi-
ments of his predecessor in this branch of physics,
the Doctor proceeded to a series of new experi-
ments, mostly conceived and instituted by himself.
The objects which he appears to have kept stea-
dily in view throughout the whole course of his
experiments and observations were, to ascertain
the nature of the animal fluid discovered by the
professor of Bologna, and to determine its influ-
ence and medium of operation in the animal eco-
nomy. In, the prosecution of these ends the Doc-
tor has doubtless displayed all that industry and
patient perseverance, so essentially requisite in the
character who would successfully inquire of na-
ture, through the medium of experiment. I am
sorry, however, to observe, that all his experiments
were not conceived and inflamed with equal in-
genuity, and perhaps I may add, not executed
with equal accuracy and definitude. Many of
[Seite 224] them appear to have been instituted without a di-
rect reference to any specific or particular end –
Equally unhappy with regard to conception, inde-
finite with respect to their nature, and inconclu-
sive in point of result, they leave no impressions
on the mind of the reader, save those of disap-
pointment regret – regret that a character of
such learning and industry should, notwithstand-
ing, interrogate nature with so little meaning, and
(I am sorry to add) with so little success.
The preceding observations must be considered
only in the light of general rules, and as such,
are liable to numerous exceptions. Many of the
experiments of Dr. Valli are, doubtless, both in-
genious and valuable; and I even entertain the
utmost confidence, that the period will yet arrive,
when the whole of them, that are ascertained
and related with justness and definitude, will be
made subservient to the establishment of general
and useful results. At present, however, they
stand in an insulated state, completely detached
from practical conclusions, and disconnected from
all known principles in physical science.
After a series of experiments sufficiently lengthy
and tedious, the Doctor conceived himself une-
quivocally authorised to conclude, that the animal
fluid of Galvani, was entirely the same with the
[Seite 225] subtle matter of electricity. This conclusion he
alleges to be the spontaneous and necessary result
of the following positions, which he delivers as
substantiated and confirmed by actual experiment.
‘“First, substances which conduct electricity,
are conductors likewise of the nervous fluid.”’
‘“2dly, Substances which are not conductors
of electricity, do not conduct the nervous fluid.”’
‘“3dly, Nonconducting bodies, which acquire
by heat the property of conducting electricity,
preserve it likewise for the nervous fluid.”’
‘“4thly, Cold at a certain degree, renders water
a non-conductor of electricity, as well as of the
nervous fluid.”’
‘“5thly, The velocity of the nervous fluid is,
as far as we can calculate, the same with that of
electricity.”’
‘“6thly, The obstacles which the nerves, under
certain circumstances, oppose to electricity, they
present likewise to the nervous fluid.”’
‘“7thly, Attraction is a property of the electric
fluid, and this property has been discovered in the
nervous fluid.”’
Having enumerated and detailed the foregoing
arguments, the Doctor, in an effusion of triumph,
subjoins, ‘“We here see the greatest analogy be-
tween these fluids; nay, I may even add, the cha-
racters of their identity.”’
As an additional support to the same opinion,
Dr Valli adduces the peculiar and striking pheno-
mena exhibited by the torpedo, the gymnotus elec-
tricus, the silurus, &c. which proceed, as he
alleges, from a fluid in every respect the same
with that which was discovered in frogs, by the
professor of anatomy at Bologna. As the Doctor,
however, has advanced nothing in confirmation of
such entire sameness, save a certain remote analogy
which he says he has discovered between the mus-
cles of animals, and the electrical apparatus of the
torpedo, the gymnotus, &c. it is obvious that this
latter argument will but very slightly impress the
philosophical physiologist, who sounds his belief
of principles on facts, rather than on vague and
visionary conjectures.
Having thus, as he supposed, satisfactorily ascer-
tained the identity of the nervous with the electric
fluid, he next proceeds to speculations on its in-
fluence in the diversified movements and functions
of the animal economy. To me, however, I must
confess, the greater part of this speculative inves-
tigation, appears to be rather the effervescent
[Seite 227] effusions of an imagination, heated to excess in a
favourite pursuit, than the solemn decisions of a
tranquil and unbiassed understanding. I acknow-
ledge myself unable, in many instances, to discern
the necessary nexus or affinity between his con-
clusions, and the facts from which they are de-
duced: – or perhaps I may speak my sentiments
more fully when I say, that the learned author
appears not unfrequently to have substituted mere
hypothetical allegations, for fair and logical conclu-
sions – the vacant results of his own conjectures,
for genuine principles developed by experiment,
and ascertained by observation. It very often
happens, that by attempting to embrace too much
under a single cause, we extend the tortured
principle beyond its natural limits, and thus, to
appearance, weaken or render doubtful its influ-
ence, even on those phenomena which it immedi-
ately regards. This observation applies with too
much propriety and force, to the speculations of
the indefatigable Valli. By attempting to explain
all, he has in fact explained none, of the pheno-
mena of the animal economy, by that subtle fluid
on which he so patiently experimented. Many of
his physiological facts and speculations are indeed
ingenious and interesting, but, in my view, they are
equally deducible from any other series of experi-
ments, as from that by which they are preceded
in the Doctor’s publication. Many of the learned
author’s facts may be, no doubt, true and well
[Seite 228] defined, and some of his principles and results to
a certain degree interesting to the physician and
philosopher, but, taken in the aggregate, they
are too disjointed to constitute any thing like a
system, too disconnected to form a regular chain
of investigation. On my mind, his speculations
on the causes of muscular motion, sensation secre-
tion and nutrition, impress no more solid convic-
tion than do those of Stahl on the subject of his
anima medica, of Van Helmont respecting his
subtle Archeus, or of the airy Paracelsus with re-
gard to his planetary influence. Notwithstanding
the apparent severity of the foregoing observa-
tions, I am still obliged to declare it as my
opinion, that the novelty and importance of the
subject on which Dr Valli has experimented and
written, entitle his work to the particular atten-
tion of the learned and ingenious of every na-
tion.
For the want of system and requisite decision in
the writings of the preceding author, compensation
is, in a great measure, made by a subsequent pub-
lication of the accurate and ingenious Fowler. The
experiments and speculations of this young philoso-
pher, on what he terms, the ‘“influence discovered
by Galvani,”’ made their first public appearance
at Edinburgh, in the course of the year 1793:
they are not, indeed, so numerous as those of the
Italian physician, but they appear to have been
[Seite 229] conceived with more design, and executed with
more judgment. Mr. Fowler seems to have been
among the first who controverted the opinion of
Galvani and Valli, respecting the identity of the
nervous and electric fluids: and he has, doubtless,
controverted it with ability and effect.
Mr. Fowler preliminates his observations, with
a lucid and forcible statement of a certain previous
combination of circumstances, which he alleges,
must have strongly prepossessed the mind of professor
Galvani, with a belief of the sameness of the pre-
ceding fluids.
That such a prepossession must have had, indeed,
a powerful effect on the subsequent deductions and
conclusions of the Professor, will be readily ac-
knowledged, by every one who has experienced
the influence of preconceived opinions – an influ-
ence pregnant with error, and leading countless
evils in its train.
Mr. Fowler proceeds then to mention the first
object which engaged his attention, in the com-
mencement of his interesting inquiry, and which
appears well calculated to pave the way, for the
more easy and effectual accomplishment of his
experimental course. This, to make use of his
own words, was, ‘“to ascertain, as well the va-
[Seite 230] rious circumstances, essentially requisite to the
production of these new phenomena, as those in
which they can be rendered most obvious.”’ The
issue of his enquiry on this subject, I will also lay
before the reader in his own words. ‘“After”’
says he, ‘“a great variety of experiments, of which
it would be unnecessary here, to relate more than
the result, I found, that I could not excite in an
animal the appearances described by Galvani, with
any substances whatever, whether solid or fluid,
except the metals: and that the mutual contact of
two different metals with each other, so far as I
was able to determine, was in every case necessary
to the effect.”’
After a satisfactory attainment of this object,
the ingenious author next proceeds to a judicious
series of experiments, with a view to discover the
genuine nature of the animal fluid, first realised by
the fortunate professor of Bologna. Of those ex-
periments he does not give us a minute specifica-
tion, but only furnishes statements of their most
obvious and striking results. These statements he
also occasionally intersperses with interesting and
important remarks, and some very ingenious spe-
culations.
Having finished his series of experiments, (a
series sufficiently numerous and diversified for the
[Seite 231] stablishment of general principles) relative to the
nature of the nervous fluid, and its affinity to the
matter of electricity, Mr. Fowler at length favours
us on this subject with the following conclusions,
which I shall take the liberty of presenting to the
reader in the words of their ingenious author.
After having stated a few analogies between the
animal fluid of Galvani, and that possessed by the
torpedo, he then reverses the comparison, and
lays down several points of essential difference,
not only between the two preceding fluids, but
also between the former of them, namely the fluid
of Galvani, and the matter of electricity.
‘“This influence, (says he, referring to the
nervous fluid of animals) differs, both from that
of the torpedo, &c. and from electricity, in pro-
ducing no sensation (in man at least) at all similar
to that of an electrical shock.”’
‘“– That some kind of disagreeable sensation
is occasioned by it, even in frogs, independent of
that which must necessarily arise from irritation
and the contractions of their muscles, is evident
from their restlessness and expressions of uneasiness.
In other animals, as I shall afterwards have occa-
sion to shew, these expressions are still less equi-
vocal: and in man we can ascertain both their
[Seite 232] degree and their kind. That they differ consider-
ably from such as are produced by electricity will
be proved when I come to speak of the effects of
this influence upon our senses.”’
‘“But the most important, and characteristic
difference which I have yet been able to discover,
between this new influence and electricity, consists
in their effects upon the contractile power of
animals and of plants. The contractions of ani-
mals excited by electricity have a tendency to
destroy that power upon which contractions de-
pend. But the contractions excited, by the appli-
cation of the metals, have, in all my experiments,
had the directly opposite effect. The more fre-
quently contractions have been in this way excited,
the longer do they continue excitable: and the
longer are the parts upon which such experiments
are made, preserved from putridity. An influ-
ence, capable of exciting contractions without
occasioning exhaustion, was a thing I so little
expected to find, and so contrary to the character
which had been given of this both by Galvani
and by Doctor Valli, that I at first distrusted my
own observation of the fact: but the number of
comparative experiments which I had afterwards
occasion to make, though with views different
from that of ascertaining the point in question,
convinced me that this influence, so far from
[Seite 233] destroying the contractility of muscles, has a ten-
dency to preserve it. Oxygene is, so far as I
know, the only stimulus in nature, whose effects
are at all analogous.”’
‘“When a frog has been long dead, I have
been sometimes more than a quarter of an hour
without being able to excite a single contraction
by the application of the metals: but after this,
without at all varying the means employed, con-
tractions have appeared, and have become gradu-
ally more and more vigorous.”’
‘“It is said (for I have never had an opportunity
of making the experiment), that a stream of elec-
tricity, passed through a sensitive plant, produces
an almost immediate collapse of its leaves. But
the influence discovered by Galvani produced no
such effect in the following experiment. Having
separated the leg of a frog from its body, I freed
its crural nerves from surrounding parts, and with
one hand held it supported upon the end of a
probe. An assistant placed a piece of silver under
its foot, and held the zinc with which it was to
be touched. A sensative plant formed the medium
of communication between us. He held the bot-
tom of its stem between his fingers, while I held
the top; so that when the silver was touched by
the zinc, the influence passed up the plant, and
[Seite 234] through the whole of its stem. The frog’s leg
instantly contracted, and repeated its contractions
every time the silver and zinc were brought in
contact: but the leaves of the plant did not col-
lapse; neither did they when any of its branches
formed part of the circuit.”’
I must however, confess that the plant, upon
which this experiment was made, had been kept
through the winter. With a young one the result
might possibly be different; but such an one I
have not yet had in my power to procure.
‘“The torpedo does not appear at all affected
by the influence which itself produces. Animals
in which Galvani’s phenomena are produced, are
strongly affected.”’
The very ingenious author passes on next to
report the result of certain experiments which he
instituted, in order to refute the opinion of those,
who allege, that the fluid of Galvani proceeds
entirely from the metallic substances used, and
does not reside at all in any part of the animal
system. In his enquiry respecting this point he
displays the same fertility in devising, the same
sagacity in judging, and the same ingenuity in
deducing, which so forcibly impress the reader
throughout every part of his experimental investi-
[Seite 235] gation. He also farther shows, that the nervous
influence of Galvani, and the subtle fluid of elec-
tricity differ very materially from each other in
the following particular, namely, that against the
effects of the former, animals are able to guard
themselves by means of a certain voluntary exer-
tion, whereas the operation of the latter is not in
the smallest degree subject to the controul or in-
fluence of the will.
Having finished the consideration of the nature,
Mr. Fowler proceeds to make some useful appli-
cations, of the influence discovered by the professor
of anatomy at Bologna. In his attempts to shed
light on certain controverted points, and to solve
certain abstruse questions, in physiology, by means
of this fluid, he appears no less ingenious and
satisfactory than in the former parts of his
enquiry.
He appears peculiarly happy and conclusive in
his researches after the source from whence the
nerves and muscles derive their respective powers.
I beg leave to lay before the reader two of the
author’s experiments, instituted for the purpose of
ascertaining this interesting particular – a particular
which has so long furnished a subject of contro-
versy among speculative physiologists. The latter
of the two experiments, (to which the former
[Seite 236] serves only as a necessary introduction) is of itself
more than equal to all that has ever been ad-
vanced on the opposite side of the question.
‘“I divided (says Mr. Fowler) the sciatic nerve
of one leg, and tied the crural artery of the other
in a large frog. Scarcely any blood was lost in
doing either. Two days after this I strangled it.
Curing the first 24 hours, the leg in which the
nerve had been divided, appeared to contract with
the most vigour; after this period the difference
between them became more doubtful; but the
contractions were at no time stronger in the leg
whose artery was tied, than in that whose nerve
was divided.’
‘The same operations were performed upon a
large female frog full of spawn. Four hours
afterwards she was covered by a male, who had
been treated in a similar manner. I mention this
circumstance, as it tends to prove, that the pain
occasioned by the operation was probably not so
great as to produce much fallacy.’
‘On the day following, she had spawned, and
on the sixth day from the operations, she was
strangled. When laid upon a plate of zinc, and
[Seite 237] excited by means of a rod of silver, the contrac-
tions were found extremely feeble in the leg
whose artery had been tied, and ceased altogether
in about twenty-two hours after her death.’
‘In the leg, whose nerve had been divided, they
appeared as vigorous as they usually are in legs
to which no injury has been previously done, and
continued excitable upwards of two days after
they had ceased to be so in the other.”’
It may be proper on the present occasion briefly
to observe, that the influence discovered by Gal-
vani was the test used by Mr. Fowler to determine
the existence or cessation of irritability in the
muscles of the animals subjected to the preceding
experiment. For this influence, as our author
judiciously observes, appears to be indeed by far
the best and most delicate test that has ever yet
been discovered for ascertaining the lowest possible
degrees of muscular irritabillity. After having
become wholly insensible to the impressions of all
other stimuli, muscles still continue to vibrate to
the kindred touches of this subtle fluid, to which
nature appears to have given them such a nice,
and, perhaps I may say, specific correspondence.
Mr. Fowler, after having transiently glanced
on the subject of inflammation, passes on to the
[Seite 238] attack of a physiological doctrine, propagated with
zeal, and supported with ability by that celebrated
experimentalist, the Abbe Fontana. The doctrine
alluded to, embraces the existence or residence of
a certain vital principle in the volume of the
blood. On this principle, as the industrious
Abbe alleges, poisons produce their instantaneous
effect, when introduced into the vascular systems
of living animals. To all the different parts of
this physical doctrine I could never yet be induced
to subscribe, notwithstanding the respectability of
its learned and numerous advocates.
By attacking and vanquishing one of its most
powerful champions, Mr. Fowler has doubtless
contributed much to its final demolition. For, in
the contest now under our immediate conside-
ration, I must confess, that to me the laurels of
victory appear to be fairly wrested from the
silvered temples of the Italian, and planted over
the youthful brow of the British Philosopher.
I have thus exhibited a view, somewhat general
indeed, though confessedly very succinct, of the
results laid down, and of the opinions entertained,
by the ingenious Fowler, on the subject of the
animal influence discovered by Professor Galvani.
To lay before the reader a full account of all that
is useful and important in the observations of this
[Seite 239] interesting author, would be to transcribe and re-
print his whole publication.
The only productions in the English language,
which this country now furnishes, professedly on
the subject of the animal fluid discovered by Gal-
vani, are (as formerly observed) those of Fowler
and Valli. On the comparative merit of those
two authors I will here take the liberty of
advancing a few general, and, I flatter myself,
impartial, observations:
The experiments of Doctor Valli are more
numerous and pompous – those of Mr. Fowler
more definite and intelligible. The former author
appears often, the latter, never, to have experi-
mented without some determinate end in view.
The experiments of the Italian may be compared
to the promiscuous plants of the forest, strewn at
random by the sportive and irregular hand of
nature – those of the young Briton, to choice and
valuable collections, arranged with order and
elegance, in a well regulated and beautiful garden.
The experiments of Valli appear to throw into
shade, those of Fowler into light, the objects
which they immediately regard. From the for-
mer, the reader collects information with diffi-
culty, from the latter, without labour or painful
attention.
In their deductions and speculations, the two
preceding authors are no less dissimilar, than with
regard to their experiments themselves. Valli is
more diffuse and often hypothetical – Fowler more
pointed and generally conclusive. Valli appears
to give loosened reins to a glowing imagination –
Fowler to be constantly under the steady guidance
of a powerful and well-cultivated understanding.
The former makes a greater display of learning,
and, therefore, too frequently views objects
through the more obscure media of previous
publications – the latter exhibits a higher degree
of ingenuity, and derives the principal part of his
information, not from pages, sanctioned only by
the names of celebrated, yet fallible, authors, but
from the great solio-volume of nature, impressed
with her own signature. On the whole, Valli
has experimented and written in the most lengthy
and profuse – Fowler in the most definite and
conclusive manner. In many parts of the writings
of the former, nothing else than the fiat of an
almighty genius would be able to bring order out
of confusion – in those of the latter, lucidity, con-
nection, and regularity, shine pre-eminent through
almost every page.
Having thus, without reserve, delivered my
sentiments on the publications of others, I hope I
may be allowed to trespass on the reader’s attention
[Seite 241] while I make a few observations relating to my
own.
Nothing could have induced me thus hastily to
forsake the humble, but secure, retreats of obscu-
rity, and risk myself before the eye of the world
in the hazardous character of an author, save a
solicitous wish to contribute to the advancement
of medical science, and thus aid in acquiring for
man a more effectual exemption from misery and
pain. I saw with regret the literary treasures of
a Blumenbach concealed from the view of my
fellow-citizens beneath the drapery of an ancient
and an obsolete language. I was anxiously
desirous to see the physiological system of that
illustrious character completely clothed in the
language of my country. I engaged in the trans-
lation of this work, not because I conceived my-
self better qualified for its execution than others,
but because others appeared to me unpardonably
remiss with regard to the undertaking. The
execution proved laborious and difficult beyond
my expectations. The difficulty of detecting an
author’s precise meaning through the dusky
medium of a Latin expression, can be fully under-
stood and realised only by him who has made the
arduous experiment.
Even after the ideas and opinions in the original
are fully embraced and completely comprehended,
another difficulty of no small magnitude still
remains, namely, to convey them to the reader
with unequivocal definitude, through the indefinite
medium of a different language. It is well known
how extremely liable we are to misapprehend the
precise meaning of an author who even writes in
our own vernacular tongue, much more so of one
who publishes in a language but little used in con-
versation, and, at best, but imperfectly understood
by any man living.
Should the foregoing translation ever fall into
the hands of the celebrated professor of Geottingen,
I hope he will receive, with candour and indul-
gence, a well meant attempt to extend the empire
of his utility and his fame, by increasing the
number of his admiring readers. If the transla-
tion be in any part erroneous, in any part defi-
cient, strictures and corrections will be thankfully
received, and punctually attended to in a second
edition of the work, should a second be demanded
by a patronising public.
To preserve as far as possible the firm and
energetic spirit which characterizes the writings
of the illustrious professor of Goettingen, and to
[Seite 143] convey to my readers the facts, the principles, the
speculations, and the opinions contained in his
original work, without even the shadow of altera-
tion, diminution, or addition, has been my steady
and uniform aim throughout the whole of the
foregoing translation. Owing, however, to the
different constitutions or idioms, as they are more
generally termed, of the Latin and English lan-
guages, my translation is in many places far – very
far from being strictly literal. Phraseology I con-
sider, at best, as the mere trappings or drapery of
composition, while facts and principles constitute its
more substantial and important part. To preserve
the latter, therefore, inviolate, and to communicate
them with the utmost definitude, is the indispen-
sible duty of a translator, from a principle of
justice to the original author, to the public, and
to himself; but in my opinion, he is not bound,
by any principle whatever, to make an entire
sacrifice of all elegance and beauty, to mere puncti-
lious literality of expression. Impressed with the
propriety and truth of these sentiments, I have,
throughout the whole of the foregoing work,
been sometimes literal and sometimes free,
accordingly as the one or the other mode of
translation gave birth to a phraseology or stile
most agreeable to my ear, and most accordant to
the spirit of the original composition.
With respect to the appendix itself, it may not
be amiss to make it the subject of a few transient
observations. The principle which these additi-
onal pages regard, and are intended to commu-
nicate, is justly becoming, among medical philoso-
phers, an object of primary importance. This
principle opens to the view of the speculative mind
a rich and spacious field, never yet printed, save
by the adventurous steps of a few pre-eminently
active and enterprising physiologists – A field, the
salutary fruits of which will, no doubt, at a future
day, serve to elucidate the nature, to develope
the composition, and to alleviate the complicated
misery of man.
My whole design in this appendix is to give a
condensed, but somewhat general view, of this
principle or influence discovered by professor Gal-
vani.
By far the greater number of medical charac-
ters in the immense tract of country embraced
within the limits of the United States, are, in con-
sequence of their distances from literary institu-
tions, excluded from access to public libraries,
and situated quite beyond the free circulation of
physical science. To such my appendix will serve
the humble purpose of a literary chronicle; it will
convey to them a brief account of the discoveries
[Seite 245] which are now going forward in the delightful
and important science of physiology.
On the subject of the influence discovered by
Galvani I have myself instituted and performed
a considerable number of experiments*; some of
[Seite 246] my results have appeared striking and new, but my
experiments have been neither sufficiently nume-
rous nor varied to warrant the deduction and esta-
blishment of general principles. My present in-
tention is (should heaven indulge me in life and
health), to prosecute to some extent this highly
[Seite 247] interesting subject. Should my investigation be
favoured with the discovery of any thing curious
in science, or useful in practice, a detail of it may
be expected in a future communication.
To my solemn audit before the bar of the pub-
lic, I now hasten in tremulous anxiety, ‘“with all
my imperfections on my head,”’ – imperfections
which will no doubt awaken the censure of the
critic, but receive, I flatter myself, the indulgence
of the liberal and candid. The approbation of
the former I neither court nor regard; that of
the latter it shall be my constant ambition to de-
serve. The professed business of most modern
critics appears to be, to condemn – promiscuously
condemn, too frequently without the faintest sha-
dow of either inclination or talents to discriminate
merit from its reverse.
In my view the approbation of a professed critic
is perfectly synonymous with the censure of the
liberal and the ingenious, to whose candid exami-
nation the preceding pages are submitted with all
that respect and deference due from an inexperi-
enced writer.
Doctor Maclurg, of Virginia, published in the year
1772, an experimental treatise on the formation, the nature
and the uses of the human bile, which has acquired for its
learned and ingenious author, no small degree of reputation
both at home and abroad. That this elaborate publication
possesses an uncommon share of merit, not even the avowed
enemies of the Doctor are themselves able to deny. The
author has shewn himself to be, at least, a very patient expe-
rimenter, and an extremely attentive observer. He appears
to have made himself perfectly master of the opinions of all
authors of celebrity and distinction, who had previously writ-
ten on the same subject. With regard to the literary merit of
the composition itself, it is doubtless entitled to the highest en-
comiums that even the most partial eulogist can bestow. The
[Seite 29] order is inimitably lucid, the style is chaste, manly and ner-
vous in the highest degree, and as to closeness and propriety
of argumentative arrangement, not even the supercilious lo-
gician himself, can find room to suggest the shadow of an
amendment.
All human compositions are, however, like the sources
from whence they originate, in some measure faulty and im-
perfect. To this general maxim, humiliating as it may ap-
pear to the pride of the self-adoring philosopher, the treatise
of the illustrious Maclurg is by no means an exception. In
several of the Doctor’s experiments there appears to be a
want of sufficient accuracy and definitude, in others a want
of object and design. Over these faults, however, consider-
able as they are in the works of an experimentalist, we feel
inclined to spread a kind mantle of palliation, when we re-
collect that our author experimented and wrote in the early
morn of scientific chemistry. Experimenters had net yet be-
come perfect adepts in their nice and momentous art; they
had not yet acquired sufficient circumspection and address to
obviate every source of fallacy, and to avail themselves of
every circumstance that might pave the way to satisfactory
and unequivocal results.
But another charge of a more weighty and important na-
ture, lies against our learned and ingenious author. He has
certainly built, on nothing more substantial than the flimsy
basis of deceptious analogy, some of the leading principles of
his favourite doctrine. Thus, for example, he supposes the
[Seite 30] bile to be a fluid, the direct result of a putrefactive degene-
racy in a portion of the circulating volume of the blood.
His most plausible reasons in support of this opinion are, first,
that the parts, from whence the incipient radicles of the vena
portarum immediately originate, contain, and communicate
with, matter already in a semiputrescent state. And second-
ly, that the bile is most abundant in quantity and most active
with regard to its quality, at that season, and under those
circumstances, which are most favourable to the commence-
ment and progress of putrefaction in the living system, as
well as in all other physical bodies.
Plausible as those arguments may, on first view appear,
they are certainly, as already observed, founded on nothing
better than fair, but fallacious analogy. The principle
which they tend to establish stands in the most direct opposi-
tion to the result of experiment – sacred experiment! the on-
ly unerring guide to conduct the candid enquirer to the ever-
lasting temple of truth. Did our learned author (I would
beg leave to ask) ever faithfully experiment on separate por-
tions of the blood, drawn from different parts of the body, in
order to determine the comparative proximity of each portion,
to the putrefactive state? I presume he never did, otherwise
his opinion on this subject would have been, doubtless, very
different from what we find in his ingenious publication.
For it is a truth, nothing the less sacred and respectable on
account of its novelty, that if equal quantities of blood be
taken from the vena portarum, and from the lungs or any part
of the arterial system, and exposed to the same incumbent
[Seite 31] circumstances, the pulmonic or arterial, will assume the putre-
factive process, much sooner than the hepatic, blood. The
cause of this phenomenon must be sufficiently obvious to any
one acquainted with the late discoveries, in the divine science
of chemistry. We would attempt its solution in the follow-
ing manner.
Vital air (which is indeed the genuine septic principle, if
any such principle exist) is in all cases essential to the progress
of putrefaction. This air, or rather its base (termed oxygene
by the ingenious chemists of France) is, as we have the strong-
est reasons to believe, from the experiments of Goodwyn,
Beddoes, Girtanner, and others, intimately blended with the
circulating blood in its passage through the lungs. As the
blood proceeds in its mazy route through the different parts
of the arterial system, it is gradually robbed of its concommi-
tant oxygene or base of vital air, by the mysterious action of
the animal system. The consequence of this spoliation is,
that the florid arterial, assumes a much darker colour, and suf-
fers finally a complete transmutation into venous blood. In
this latter state the putrefactive process is less apt to com-
mence, because the blood contains less oxygene in a state of
intimate mixture, or perhaps I might with more propriety
say, in a state of combination. For in proportion as the base
of vital air is more intimately blended with, and therefore
more nearly approximated to, the constituent parts of the
blood, the more powerfully can it co-operate with other aux-
iliary agents, in inducing these parts to assume that intestine
motion, which constitutes the putrefactive process. Although
our learned author is decidedly of opinion, that putrefaction
commences more readily, if vital air be excluded altogether
[Seite 32] from the putrefying substances, yet it is now well known,
that the very reverse of this is true. Exclude vital air from
a body, in the composition of which none of this energetic
fluid exists, and you thereby embalm that body in a degree
equal, if not superior to the embalmment of the unperishable
mummies of the East.
No body, whatever, is capable of taking on the putrefac-
tive process, that does not contain in its composition more
or less of those simple substances that belong to the class of
inflammables. Reasoning therefore a priori, or climbing the
arduous steeps of science by the more laborious steps of expe-
riment and observation, we are warranted in either case to
conclude, that putrefaction consists, in a very considerable
degree, in the intimate combination of the base of vital air to
certain substances of an inflammable nature. Both the pri-
mary elements of which putrefiable bodies are composed, and
also the results of actual putrefaction, co-operate in the esta-
blishment of the same conclusion.
It is certainly a truth, that vital air is as essential to the
putrefactive process as it is to the support of combustion, or
the continuance of animal life.
Upon the whole, we may without the smallest hesitation
conclude, that the former opinions of physiologists respecting
the supposed putrescent disposition of the hepatic blood, are
wholly insupportable by argument or fact, being indeed di-
rectly opposed to the literal result of positive experiment;
[Seite 33] and therefore, that the pious eulogia so profusely bestowed
on the powers of the animal economy, in being able to form
an antiseptic out of a highly putrescent fluid, appear to be as
visionary and hypothetical, as nature’s final intention in the
preparation of this fluid was thought to be beneficent, and her
process itself beautiful, and interesting.
A species of fungus, denominated phallus, from its strik-
ing similitude to the male penis.
For a great number of truly important observations
and highly interesting speculations on this subject, the reader
is referred to a short treatise, written by Charles Darwin,
‘“On the retrograde motion of the lymphatics,”’ and pub-
lished at Litchfield m the year 1780, a considerable period
of time after the premature death of its ingenious author.
This young philosopher and physician appears to have been
peculiarly formed by nature, and happily finished by edu-
cation, to shed unequivocal light on subjects of a dark and
difficult nature in the science of medicine. He experimented
with accuracy and definitude, he observed with the utmost
attention, and he speculated with the highest ingenuity and
force. Unhappily for the healing art, and (perhaps I may
add) for science in all its various branches, this amiable
young philosopher was hastily summoned away, ere yet his
mind was perfectly expanded, or his plenitude of merit
announced to the world.
That the reader may not be entirely ignorant of what is
meant by a prepared frog, I take the liberty of presenting
him with the following brief extract from the first experi-
ment detailed in Dr. Valli’s publication: ‘“My first experi-
ment was made on a frog, in the following manner: I opened
the abdomen in order to lay bare the spine of the back, and
discover the crural nerves which issue from it; a few lines
above this point I cut the animal in two, and by passing my
scissars immediately under the origin of these nerves, re-
moved the remaining portion of the vertebral column, so
as only to leave the vertebrae which united the bundle of
nerves. Having enveloped this portion of the vertebrae with
a piece of sheet lead, with one end of a metal conductor, I
touched the coated part, and with the other the surface of
the thighs, which had been previously stripped of the skin.
The movements were violent, and continued for a long time,”’
&c. In general, throughout the whole of this physician’s
experimental treatise, when one or more of the nerves of an
animal are coated with sheet-lead or any other metal, that
animal is said to be prepared.
That the reader may be acquainted with an easy, cheap
and familiar method of experimenting on this subject, with-
out having his feelings hurt by the agonizing pangs of tor-
tured and dying animals, I will here take the liberty of in-
serting, in form of notes, a few extracts taken from a com-
munication transmitted to Mr. Fowler, by his learned friend
Mr. Robison, professor of natural philosophy in the univer-
sity of Edinburgh.
A variety of other experiments of a similar nature are
contained in the same communication from Mr. Robison
to Mr. Fowler; but a further detail of them I conceive un-
necessary, as the ingenious reader, being acquainted with
the foregoing, can with facility devise other experiments
for himself. Thus I have frequently conveyed to my eye
the luminous flash mentioned by Mr. Robison, not only
from the internal vestments of the mouth, the nose, the ure-
thra, &c. but also from between my fingers, from the cu-
bital flexure of my arm, and from various other parts of
my body, where the texture of the cuticle and skin is more
fine and soft than ordinary; always taking care, however,
to moisten the part previously to the application of the
metals.
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