1. Account of the Snow Ophthalmia, with the methods employed
for preventing it.

Xenophon, in his account of the expedition of the younger
Cyrus, relates, that when the Grecian army was crossing the
snowy mountains of Armenia, between the Euphrates and Pha-
sis, in the middle of winter (which answers to the beginning of
January according to our present mode of dividing time), many
of the soldiers were blinded by the insupportable brightness
of the snow; and that, with the intention of preventing or
curing this annoying affection, they bound something black
(μελαν τι) before their eyes^*.

It appears that this snow ophthalmia, of which we sometimes
see examples even among ourselves in the winter season, is en-
demic in alpine and northern countries; so that the Laplanders,
when returning from the chase of the wild rein-deer, are for
some days almost entirely destitute of sight^†. The Greenland-
ers are affected with this disease of the eyes chiefly in the
months of May and June, and if it continue longer, they at-
tempt its cure by making an incision in the skin of the upper
eyelid^‡. The Esquimaux labour under this ophthalmia more
especially when the surface of the snow, which covers the ground
on all sides, has been partially melted, and again, by the action
of frost, converted into a solid crust. To the incapability of
bearing light, there is at first joined a disagreeable sensation, as
if grains of sand had fallen into the eyes, which, as the disease
advances, increases so as to resemble the effect of the strongest
[Seite 260] sternutatory powder, and they are seized, at the same time,
with a very violent tonic blepharospasmus. These affections
sometimes, though rarely, disappear in ten days, but not unfre-
quently they remain for four weeks^*.

Of the mechanical remedies used by the savages to prevent
this blindness, which results from an intense glare of light re-
flected from the snow, I may mention two which happen to be
at hand; one of them is of the same kind as that mentioned by
Xenophon, and is at the present day much in use in those
northern countries, – something black, which is stretched before
the eyes; that is, a sort of net-work or gauze, made of horse-
hair, a little convex anteriorly, lest it should impede the free
motion of the eyelids. There is a specimen of this preventive
machine among the curiosities of our academic museum, pre-
sented by M. De Asch, to whom I am indebted for innumerable
articles supplied to my collection of natural objects, with a note
attached, signifying that it is in use among the Tartars, espe-
cially when hunting or travelling in winter, and that it is called
in their language Kaar-yoeslik, which means eye-bandage^†.

The other of these machines is constructed on a very diffe-
rent plan by the Esquimaux, on the coast of Labrador. Al-
though we find many things related by Ellis, Crantz, and other
authors, who have visited those eastern shores of America, re-
garding the wonderful sagacity with which the Greenlanders
and Esquimaux construct their snow spectacles, or snow eyes,
as they call them; yet, as they seemed to be neither very accu-
rate nor clear, I applied to one of the missionaries that he
might give me a more correct account of the matter, in as far as
regarded the part of the country in which the colonies of his
brethren had been established. This benevolent man afforded
me the necessary information, and moreover sent me a specimen
of those spectacles, made by the Esquimaux themselves of the
colony of Hoffenthal, on the Labrador coast, and which, both
[Seite 261] with respect to simplicity of design, and accuracy of adaptation
to the end in view, testifies the great ingenuity and acuteness of
these savages in alleviating the inconveniences of their mode of
life.

A few words will suffice to illustrate the figures by which this
machine is represented. It is made of a very smooth wooden
substance, like poplar, of that remarkable, and, in as far as
regards its origin, as yet enigmatical, kind, which is driven
upon the northern shores of the globe. The posterior sur-
face, which covers the nose, is pretty deeply cut, to pre-
vent it obstructing the free motion of the eye. There is a
notch cut on each side, at the lower margin, which is applied to
the cheeks, and which is scarcely subservient to any other
purpose than to afford a passage to the tears, which are rapidly
secreted in an inflamed eye. The upper margin of the fore
side, is more prominent than the under, so as to protect the
eye from the snow, or act as a shade in keeping off the sun’s
rays. The other side is blackened with soot, so as to ab-
sorb a part of the dazzling light. Lastly, the apertures made
for vision are in the form of narrow slits, and so placed as
to correspond with the eye, having the lids nearly closed. I
have of late, unfortunately, had occasion to try this machine,
being troubled with a severe and obstinate tonic blepharospas-
mus, which has continued for several months; and when it was
necessary for me to look minutely at anatomical preparations,
or other natural objects, in a clear light, I have found nothing
of equal assistance, or so convenient, as these Esquimaux spec-
tacles of which we speak. Moreover, what all have testified,
who, seeing this machine in my museum, have made trial of it,
– it answers the purpose of a telescope; and Ellis says, that
the savages just mentioned, although they are less dazzled by
the brightness of the snow, apply it to their eyes only with the
view of observing remote objects more distinctly^*.

2. Remarkable Irritability of the Tongue.

We shall begin with Ovid’s description of the very lively ir-
ritability in a tongue that had been newly cut out, when he re-
[Seite 262] lates the cruel deed of Tereus King of Thrace, perpetrated up-
on Philomela the sister of his wife Procne^*.

Which, in truth, I had been accustomed, as often as I read it,
to refer to the well known licence of poets, who assume an equal
power with painters in matters of this kind, until my own ocular
experience taught me, that the description was in no way incon-
sistent with truth.

For when, contrary to the opinion which I had hitherto held,
concerning the remarkable irritability of the tongue of men, and
of other mammalia, I saw that Sir Everard Home, who has dis-
tinguished himself by his physiological investigations, so much
diminished the vis insita of the organ in question, as to pro-
nounce its muscular fibres to possess a smaller degree of irritabi-
lity than almost any other part of the body^†, I determined to
satisfy myself regarding this point, as well by instituting experi-
ments myself, as by consulting the observations of others.

And nowhere did I expect to find a richer harvest of obser-
vations upon this point, than in the numerous writings on the
subject of the Hallerian irritability, in which innumerable ex-
periments, instituted with the view of supporting or of subvert-
ing the doctrine of muscular excitement, are described.

But as it not unfrequently happens, with regard to disquisitions
of this kind, that one may find among them every thing but
just what he wants, this I found to be the case here also; and
I was not a little surprised, that nothing occurred, either in the
writings of the first President of our University, on the subject
of his celebrated discovery, the heads of which are contained in
the commentaries of the Royal Society, or in the works of others,
whether his supporters or adversaries, in the way of experiment
or observation upon the irritability of the tongue.

[Seite 263]

Nor was I more fortunate in searching the writers upon Gal-
vanism, as it is commonly termed, in which also I found my-
self baffled in the hopes which I had cherished.

In the great and immortal physiological work of Haller,
which may be considered as forming the pandect of that study,
all that is said upon the subject is contained within the short
limit of a remark of three words, namely, ‘“irritabilitate lingua
gaudet,”’ the tongue possesses irritability^*.

As nothing, therefore, was to be gained by consulting authors,
I began the more diligently to observe for myself, and, whenever
an opportunity presented, cut out the tongues of warm-blooded
animals, which had been killed for other purposes, of dogs, cats,
goats, sheep and rabbits, and in all these, although there was
a considerable difference in different individuals, even of the
same species, I was struck with the irritability of the yet warm
tongue, under the excitement of chemical as well as mechanical
stimuli; of which experiment I may adduce one in the present
place, as exactly corresponding with the description of Ovid.

I had the tongue of a four-year-old ox, which had been killed
in the common way, by opening the large vessels of the neck,
cut out in my presence, while yet warm, and at the same time
the heart, in order that I might compare the oscillatory motion
of this organ, which is by far the most irritable that we are ac-
quainted with, with the motion of the tongue. And when I ex-
cited both viscera at the same time by the same mechanical sti-
muli, namely incisions of a knife, and pricks of a needle, the di-
vided tongue appeared to all the bystanders to survive the
heart, by more than seven minutes, and to retain the oscillations
of its fibres altogether for a quarter of an hour; and so vivid
were the movements, when I cut across the fore part of the
tongue, that the butcher’s wife compared them to those of an
eel in a similar condition, quite in the way that Ovid has com-
pared them to the motions of the tail of a mutilated snake.

To these observations made upon animals, I may add here a
similar one made upon the human tongue itself, the knowledge
of which I owe to my excellent friend and much respected col-
league, Reimar.

[Seite 264]

A boy in Hamburgh, who was severely affectted with epilepsy,
bit the fore part of his tongue in a violent paroxysm, in such a
manner that it adhered only by a thin slip. This segment,
therefore, as being not only useless, but very inconvenient to the
patient, it was immediately judged necessary to cut off: And
when the physician, the illustrious Chaupefié, placed it upon
his hand, he was surprised to see it palpitate strongly. In order,
however, to guard against all deception, as the motion might
have depended upon the action of the muscles of his hand, he
placed the bit of tongue in the bottom of a window, and even
then it continued to move for several minutes, insomuch that
it even seemed, as all the bystanders testified with one accord,
to change place a little, and creep forward. External stimuli,
the prick of a needle, or the application of salt, also excited
similar motion; scarcely, however, differing in any way from the
spontaneous ones.

I am therefore much mistaken, if the muscular substance
of the tongue is not possessed of a remarkable degree of ir-
ritability; and Ovid has described its phenomena with exquisite
precision.

3. The Xanthoöpia of Jaundiced Persons.

The opinion that objects are seen by people affected with
jaundice of a yellow colour, has been so generally prevalent, for
nearly two thousand years, that it has metaphorically passed
into a saying. More particularly known is the passage of
Lucretius on this subject:

In the same manner his cotemporary Varro says, that jaun-
diced and lethargic people see things, which are not in reality
yellow, just as if they were so; and after these Galen^†, and his
numberless followers, down to Boerhaave^‡, and his adherents.

[Seite 265]

Mercurialis^* was the first, in as far as I know, who called this
assertion, regarding the yellowish vision of those who labour un-
der icterus, in doubt; and in later times Haller^†, and Mor-
gagni^‡, among others, have been similarly inclined.

Lastly, a middle opinion between the two has been held
by many after Hoffmann^§, Durazzini, Buzzi, and Percival^‖,
who acknowledged, that the yellow vision in question does in-
deed occur in some cases of icterus, though rarely, and who
placed the fact beyond dispute by accurate investigation, as well
as occasionally by anatomical dissection of the eyes of pa-
tients who died of jaundice.

But, on consulting all these opinions with care, that rarer
Xanthoöpia (as it may be called) of jaundiced persons, sems to
be in this condition, that it supposes at first a yellowish tinge in
the pellucid media which transmit the rays of light, especially of
the aqueous humour and crystalline lens; then a not so gentle,
but more sudden attack or increase of the disease; and, lastly,
both a vivid perception in the sensorium and application of the
mind. But as these seldom happen at once in icterus, we can
easily comprehend why very few patients in that disease com-
plain of the yellow tint of objects. On the contrary, I knew a
lady of excellent talents and accomplishments, who, on a sudden
and severe attack of icterus, saw at first linen of all kinds,
towels, etc. of a livid or dusky hue, and as if they had been ill
washed, or not properly bleached. But those, upon whom the
disease seizes slowly, advancing as it were step by step, no more
experience this yellow hue of objects than old people do, in
whom we have known the crystalline lens become livid in very
advanced age. Should this tinge take place in one eye only, the
other remaining uncontaminated, that diversity of colour in white
and shining objects, would be no less easy of observation, than in
[Seite 266] patients, who, after depression of cataract, see the objects, from the
use of sulphate of copper applied to the diseased eye, on which
they look with it, of a colour sometimes verging towards blue^*.
And a somewhat similar vitiation of sight is known to take place
in those who have, for a long time, kept one eye applied to diop-
trical instruments. Thus the celebrated philosopher, James
Rohault, after looking, without interruption, for twelve hours,
at a distant battle, by means of a telescope, from that time
forth saw every object with his right eye, which he had here fa-
tigued so much, of a different colour from what it had when
viewed with the left. And the same circumstance happened to
myself, after being assiduously employed, for several days, in
making observations with a compound microscope.

But what is commonly told of the two celebrated painters,
J. Jouvenet^† and Gavin Hamilton^‡, does not appear at all like-
ly, viz. that they did not apply the colours with great precision
in their paintings, because they both laboured under a similar
organic disease of the eyes, and so could not depict the colours
of objects with the accuracy of nature. For although we allow
a disease of this kind, yet we cannot but think that they saw
their own paints in the same way that they saw the objects
which they painted, so that they ought to appear to the specta-
tors tempered in an equal manner, and so as to correspond with
nature.

4. On the Prickle at the extremity of the Tail of the Lion.

Homer^§, and many other ancient poets, both Greek and La-
tin, when they describe an enraged lion, relate that, as Lucan
says^‖, he stimulates himself with blows of his tail. And Pliny,
indeed, calls the tail the index of the lion’s mind; for, says he,
‘“when the tail is at rest, the animal is quiet, gentle, and seems
pleased, which is seldom, however, the case; and anger is
much more frequent with him, in the commencement of which
he lashes the ground, but as it increases, his sides, as if with the
[Seite 267] view of rousing it to a higher pitch^*.”’ Again, Alexander
Aphrodisiensis has among his problemata the following: ‘“Why,
since the moving of the tail is, in most animals, a sign of their
recognition of friends, does the lion lash his sides when enraged,
and the bull in the same manner?”’^†

But the ancient commentator of Homer, who commonly goes
by the name of Didymus Alexandrinus, asserts, with reference
to the place of the Iliad, which we have cited, ‘“that the lion
has a black prickle in its tail among the hair, like a horn, when
punctured, with which it is still more irritated by the pain^‡.”’
This opinion, however, which has been noticed also by late
commentators^§, we were the more disposed to take for a mere
fiction, that no anatomist, who had possessed an opportunity of
dissecting a lion, had hitherto made mention of any prickle of
this kind^‖.

I had the good fortune, however, when, through the muni-
ficence of a friend, to whom I owe so many splendid ornaments
of my cabinet, I was presented with a lioness, which had died
very soon before, to find, in consequence of an anxious search
which I had made, in order to satisfy myself regarding the as-
sertion of the Greek scholiast, a very small dark-coloured
prickle in the very tip of the tail, as hard as a piece of horn,
and surrounded at its base with an annular fold of the skin;
and when I cautiously dissected the hide in this place, I found
a singular follicle of a glandular appearance, to which the
prickle firmly adhered. (See Plate IV. Fig. 8. in last Num-
ber.) All these parts, however, were so minute, and the little
horny apex so buried among the tufted hairs of the tail, that
the use attributed by the ancient scholiasts cannot be regarded
[Seite 268] as any thing else than imaginary; but the structure of the or-
gan is so elegant, and its form so regular, that it cannot pos-
sibly be considered as fortuitous, or what is commonly called
a lusus naturae. I leave to others, who may have an oppor-
tunity, to inquire whether any variety be observable in its con-
formation and size, as connected with a difference of age or
sex^*.

5. Domestic Sheep again become Wild.

As some kinds of domestic animals, hogs, for example, cats,
rabbits, etc., are evidently referable to their original stocks,
so, on the other hand, there are many others which seem so
much altered from their original state, that they are now no-
where to be seen in nature, that is, in a wild state, nor can we
pronounce with certainty what was their native country. Thus,
it is impossible to say with precision, what was the original coun-
try of the horse or dog, provided care be taken not to confound
the offspring of tame individuals, which have got loose and re-
tired to uncultivated places, with truly wild animals, which have
been so all along from their origin. For, to mention an ex-
ample, whole herds of wild horses are now found in the woods
of Paraguay, although, as is well known, no animals of the
species existed in the New World, before the first arrival of the
Spaniards there. In the same way, the classic Oviedo, one of
the first writers on the New World, mentions that other species
of domestic animals, dogs, cats, oxen and hogs, which had been
brought to America by those Europeans who first took posses-
sion of it, had afterwards become wild by chance, and had pro-
pagated^†.

In the same manner, numerous cases have been observed in
Europe, of dogs, cats, goats, oxen and horses. Only of the
sheep no example had hitherto occurred to me^‡, until, perusing
[Seite 269] the very learned work of Vincentius, I fell upon the remarkable
place where Nearchus, in his description of a sea voyage, re-
lates, regarding the island Cataia, which was desert, and conse-
crated to Mercury and Venus, situated on the coast of Carma-
nia, that the inhabitants of the neighbouring islands carried
thither sheep and goats yearly, and sacrificed them to the god
and goddess, and that these animals, in course of time, became
wild in the deserts^*. Concerning the wild sheep in Phrygia,
of which Varro^† mentions that many flocks are seen there, I
cannot presume to decide. In the mean time, however, even
these may be considered as domestic sheep run wild, with
greater probability, than as being of the Capra Ammon species,
as was the opinion of Pennant.

6. The Genuine Opsian Stone.

Not to leave Mineralogy altogether untouched in these mis-
cellaneous notices, we embrace the opportunity of adding a few
words regarding the Opsian Stone, afforded by the Periplus Maris
Erythraei, which accurately points out the native place in which
this fossil occurs on the coast of the Arabian Sea^‡. And, as
I learned from the classical commentaries of the Dean of
Westminster on the subject^§, that the illustrious Salt, so cele-
brated for his travels in Ethiopia as well as in Arabia and the
Indian Peninsula, had visited that place, found the opsian stone
there, and brought it to England, and being desirous of seeing
this hitherto problematical fossil, I was presented by our accom-
plished colleague with two his specimens, which the above
celebrated traveller had gathered on the sandy shores of the
Ethiopian Gulph Howakih, North Lat. 15°10′, in the month
of January 1809^‖; and which I was convinced would, at first
sight, settle the various dissensions regarding the opsian and op-
[Seite 270] sidian stone^*, as will appear from the oryctognostic description,
made up from the specimens which I have in my possession.

The colour of this stone was raven-black; but on one sur-
face of polished specimens there was an appearance of parallel
streaks, of a somewhat paler colour.

The form in which it occurs is subglobular, obtusely angu-
lar, which is compared by Vincent to that of a potato.

The size of the specimens is that of some inches in diameter.

Lustre intermediate between pitchy and glassy.

Fracture small conchoidal.

Opaque, unless in very thin plates, which, in the light of a
candle, are somewhat translucent, passing from grey to deep
leek-green.

Hardness very great, admitting a high polish.

Specific gravity, 2.410.

All these circumstances, in short, demonstrate, that the genu-
ine Aethiopic opsian stone, again discovered of late years, but
hitherto seen by very few mineralogists, is identically the same
with the common Obsidian, which used formerly to go by the
improper name of Iceland Agate.