fact which may cause our native city to feel the glow of shame. Of all her literati, her men of benevolence, taste, and riches, seventy only, to the period of the author's decease, had the liberality to countenance him by a subscription, more than half of whom were tradesmen, artists, and those of the middle class of society; whilst the little city of New Orleans, in the short space of seventeen days, furnished sixty subscribers to the American Ornithology!

Mr. Wilson was possessed of the nicest sense of honour. In all his dealings he was not only scrupulously just, but highly generous. His veneration for truth was exemplary. His disposition was social and affectionate. His benevolence extensive. He was remarkably temperate in eating and drinking: his love of retirement preserving him from the contaminating influence of the convivial circle. And, unlike the majority of his countrymen, he abstained from the use of tobacco in every shape. But as no one is perfect, Mr. Wilson in a small degree partook of the weakness of humanity. He was of the genus irritabile, and was obstinate in opinion. It ever gave him pleasure to acknowledge error when the conviction resulted from his own judgment alone, but he could not endure to be told of his mistakes. Hence his associates had to be sparing of their criticisms, through a fear of forfeiting his friendship. With almost all his friends he had occasionally, arising from a collision of opinion, some slight misunderstanding, which was soon passed over, leaving no disagreeable impression. But an act of disrespect, or wilful injury, he would seldom forgive.

Such was Alexander Wilson. When the writer of this humble biography indulges in retrospection, he again finds himself in the society of that amiable individual whose life was a series of those virtues which dignify human nature; he attends him in his wildwood rambles, and listens to those charming observations which the magnificence of creation was wont to give birth to; he sits at his feet, and receives the instructions of one, in science, so competent to teach; he beholds him in the social circle, and notes the complacency which his presencé inspired in all around. But the transition from the past to the present quickens that anguish with which his heart must be filled, who casts a melancholy look on those scenes a few months since graced with the presence of one, united to him by a conformity of taste, disposition, and pursuit; and whe reflects that that beloved friend can revisit them no more.

It was the intention of Mr. Wilson, on the completion of his ornithology, to publish an edition in four volumes octavo, the figures to be engraved on wood, somewhat after the manner of Bewick's British Birds, and coloured with all the care that has been bestowed on the original plates. If he had lived to effect such a scheme, the public would have been put in possession of a work of considerable elegance as respects typography and illustrations; wherein the subjects would have been arranged in systematical order, and the whole at a cost of not more than one-seventh part of the quarto edition.

J

He likewise contemplated a work on the quadrupeds of the United States; to be printed in the same splendid style of the Ornithology; the figures to be engraved with the highest finish, and by the best artists of our country. How much has science lost in the death of this ingenious and indefatigable naturalist!

Mr. Wilson was interred in the cemetery of the Swedish church, in the district of Southwark, Philadelphia. While in the enjoyment of health, he had conversed with a friend on the subject of his dissolution, and expressed a wish to be buried in some rural spot sacred to peace and solitude, where the charms of nature might invite the steps of the votary of the Muses and the lover of science, and where the birds might sing over his grave.

It has been an occasion of regret to those of his friends to whom was confided the mournful duty of ordering his funeral that his desire had not been made known to them, otherwise it should have been piously observed.

ARTICLE II.

Chemical Analysis of some Membranous Bodies of Animals.
By Professor I. F. John.*

THE substances of which I propose to speak in this paper are the epidermis, nails, horns, claws, hoofs, feathers, &c. Though they have been often examined by chemists, as is evident from the great number of examples which I have given in my Tables of the Animal Kingdom, published in Berlin in 1814, yet it will very soon be remarked that there is not a single experiment which fully comes up to our wishes; for all that we at present know is that they consist of an insoluble substance combined with some phosphate of lime. Respecting the nature of this insoluble substance we are still in the dark, and do not know whether, according to the opinion of Fourcroy and Vauquelin, it consists of indurated mucus; or of fibrin, as Scherer and Hildebrant conceive; or of albumen, as Hatchett thinks he has ascertained; or, as I conceive, of modifications sometimes of one, sometimes of another, of these bodies.

As to this last opinion, it will be very difficult to establish it. Indurated mucus, indurated albumen, and animal fibrin, may be distinguished from each other by striking chemical properties when we possess each of them in a state of purity. But the many striking properties which they possess in common, and the passage from the one to the other, so frequent in animal bodies, make it very difficult to distinguish them from each other, and lead to the opinion that they are modifications of the same constituents. When

* Translated from Schweigger's Journal, vol. xiv. p. 302, October, 1815.*

in a state of solution, they exhibit quite different properties, and are easily distinguished; but when they become insoluble, they do not appear to undergo merely a coagulation or condensation, but to assume quite different chemical properties. Several facts lead to the conclusion that fibrin contains the greatest proportion of azote; that albumen follows next in this respect, while mucus contains the least. But as these differences are but small, it is difficult to render them sensible by analysis. This character seems likewise to be much influenced by the solvent; for hair, which, according to Vauquelin's analysis, consists almost entirely of mucus, contains, however, not less azote than albumen does. The phenomena which these bodies exhibit when they undergo spontaneous decomposition, their relation to different acids, and to water, the effects of a high temperature, of a dry distillation, &c. may afford marks of distinction to practised chemists; and these are the characters which I employ in my experiments.

It is very much to be desired that chemists would prosecute this subject till accurate characters be ascertained by means of which these three substances may be distinguished from each other; for the advantages resulting from such a discovery would not be confined to chemistry, but would extend likewise to physiology, as consequences might be drawn from it respecting the source of the formation of these matters. But I must not prosecute this subject any further, that I may not appear to deviate from the object which I have in view.

1. Epidermis of the Foot.

(a) When boiled in water, about five or six per cent. were dissolved. When the concentrated solution was left in the temperature of 77°, it dried to a yellowish, transparent, tough mass, in which a number of small crystals were visible, though they could not be separated.

The concentrated solution acted as an acid on litmus paper. On cooling, it gelatinized very imperfectly. It was precipitated by solutions of mercury, silver, lead, and oxalic acid. Tincture of nutgalls occasioned scarcely any precipitate; and barytes, ammonia, and alcohol, none at all. Lime caused a smell of ammonia to exhale. Hence it contains neither a sulphate nor phosphate of lime. An acid, a trace of gelatin, and mucus, were its principal ingredients.

From the dried mass of the decoction alcohol dissolved, besides an uncombined acid, some salts, which separated in crystals. This acid possessed all the properties of the acid discovered by Scheele in milk, and afterwards by Berzelius in different animal substances, and known by the name of lactic acid.

(b) The portion of epidermis which is insoluble in water appeared, after the boiling, snow-white, and prodigiously swelled. It dissolved completely in nitric acid, and produced much oxalic acid. When heated, it dried to a very hard skin, which possessed

its natural semi-transparence, and in a higher temperature it fused. It dissolved very speedily in a caustic ley. The boiled epidermis being distilled, gave out, like albumen, first a fetid ammoniacal liquid, then a yellow oil, much concrete salt, and the usual gaseous products, without a trace of an acid. When allowed to putrefy, it exhibited the same appearances as albumen, to which in all its other properties it has the closest resemblance.

(c) By incineration about per cent. of a reddish ash was obtained, from which water dissolved a little potash, and sulphate, muriate, and phosphate, of potash. There remained behind a reddish residue, from which nitric acid dissolved a trace of phosphate of lime. What remained consisted of gypsum, with traces of iron, and, as it seemed, of manganese.

Chemists usually suppose, when they find no sulphate of potash among the salts obtained by the moist way, though it constitutes an ingredient of the ash, that this proves the presence of sulphur in the substance under examination. For my part, I am of opinion that to establish such a position much more accurate experiments would be requisite than have hitherto been made. In the present case it is easy to conceive that the presence of sulphate of potash in the ash is owing to the decomposition of gypsum.

(d) On treating the epidermis with alcohol, at a temperature between 77° and 100°, only per cent. of a fatty matter was dissolved, which was precipitated by water, and separated by evapo

ration.

A hundred parts of the epidermis of the human foot are, there, fore, composed of the following constituents :

Indurated albumen....

.93 to 95

Mucus, with a trace of animal (gelatinous?) matter.. 5

Lactic acid

From this analysis, it follows that Hatchett's determination, that it consists of indurated albumen, is correct. It is very probable that the epidermis is formed from the lymph contained in the lymphatic vessels that pass through the skin. By strong friction, as takes place in several mechanical handicrafts, by much walking, &c. these vessels are probably ruptured in great numbers. Hence the great thickening of the cuticle which takes place in such cases. The fatty matter contained in the epidermis seems intended to

keep the surface always moist and smooth. It is this matter which in summer frequently makes its appearance in considerable quantity in the sweat as a liquid oil. In some diseases, in which the nails, skin, &c. become brittle, this fatty matter seems to be wanting, or to be diminished in quantity.

HI. Epidermis from the Arm of a Woman who was afflicted with

Herpes.

This woman had formerly been afflicted with different diseases, and was probably labouring under phthisis. More lately she had a scaly eruption, possessing the characters of herpes. It occasioned the whole epidermis to become loose, and at last it appeared dead. When the woman expired, fatty masses were found in different places under this covering, probably proceeding from the muscles below.

The dried leprous epidermis had a light, but dirty, yellowishgreen colour; but during the life of the woman it had been greyishgreen. It appeared to be composed of very fine scales laid upon each other, and had a resemblance to shagreen, It was not scurfy, but supple, like the healthy epidermis, though unequally thick. Being treated exactly as in the preceding analysis, I obtained

This epidermis did not fuse, like the preceding, which I had collected by degrees from the hard parts of the foot, and it gave by incineration a white ash which did not exceed per cent.

When boiled in water it exhibited the same properties as the healthy epidermis, excepting that it produced an unusual quantity of froth, which appeared to be owing to the mucus.

It was likewise distinguished from the healthy epidermis by a greater proportion of fat, and by the gelatinous mucus which the healthy epidermis does not contain, and which seems in general to be a mark of much local disease. Probably the small scales lying on each other, with which the outer surface was covered, and which gave it a rough appearance, consisted of the gelatinous mucus indurated. It no doubt proceeded from the exhaling vessels at the same time with the perspiration. This gave the patient a very fetid odour. After I had completed my analysis, I learned that M.