CHEMICAL NATURE OE SKIN SECRETIONS. 675 
Sotnitschewsky, 1 in an analysis of a dermoid cyst of the ovary, found 
tripalmitin, tristearin, and triolein : soaps of the acids of these fats and 
of caproic and caprylic acids, albumin, cholesterin, and an alcohol of 
high molecular weight, which, however, was not oetyl alcohol.- Tyrosine, 
hypoxanthin, xanthjn, sugar, and glycogen were absent. 
The vernix easeosa of man, according to Euppel 3 and Liebreich, 4 con- 
tains cholesterin fats of oleic and palmitic acids, as well as glycerin fats, 
and also free cholesterin and isocholesterin. 
The cerumen of the ear has been investigated by Petrequin, 5 and is 
found to contain potash soaps of oleic and stearic acids in the case of man 
and the ox, while in the dog the base is lime, and in the horse magnesia. 
Wool fat, the sebaceous secretion of the sheep's skin, was proved by 
Hartmann' 3 to contain no glycerin fats, but only those with cholesterin 
as alcohol. Sdiulxe and Urich 7 confirmed this, and also found free 
cholesterin and isocholesterin. 
These cholesterin fats (so-called " lanoline ") have been speeia Un- 
investigated by Liebreich, 8 who finds that they are associated with 
keratinised structures', and are not necessarily formed in sebaceous 
glands, but may be formed within epidermic cells. Tortoiseshell, whale- 
bone, horn, quills of porcupine and hedgehog, hoof of horse, and beak of 
crow, all contain these fats. The skin of the two-toed sloth has no sebace- 
ous glands, and yet contains cholesterin fats, while pigeons bereft of 
their uropygial glands still have these substances in their feathers. 
Such fats are peculiar, in that they can take up more than their weight 
of water, and also in that they do not become rancid, and offer a 
complete protection against the entrance of micro-organisms. Liebreich 
compares them to the wax of plants, which is an ether of a monohydric 
alcohol with a fatty acid. 9 
The secretion of the tail gland of the bird 10 has been chemically investi- 
gated by de Jonge. 11 
The secretion contains cetyl alcohol, the alcohol of spermaceti. Xo sugar 
or urea is present. Geese deprived of the tail gland and immersed in water are 
found to take up from two to two-and-a-half times as much water in their 
plumage as normal birds'. 12 
The so-called "pigeons' milk," with which the young birds are fed by b tth 
parents during the earlier days of life, is practically a sebaceous secretion of 
temporary glands formed in the lateral pouches of the crop in both cock and 
1 Ztsehr. f. physiol. Chcm., Strassburg, 1880, Bd. iv. S. 345. 
2 Ernst Ludwig (Ztsehr. f. physiol. Chcm., Strassburg, 1897, Bd. xxiii. S. 38) has quite 
recently found cetvl alcohol in the contents of dermoid cvsts of the ovary. 
3 Ibid., 1895, Bd. xxi. S. 122. 
4 " Verhaudl. d. Berl. physiol. Gesellsch.," in Arch. f. Physiol., Leipzig, 1S90, S. 363. 
5 Comfit, rend. Acad. d. sc, Paris, 1869, tome lxix. p. 987; also 1869, tome lxviii. 
p. 910; Jahresb. ii. d. Fortschr. d. Thicr-Chem., Wiesbaden, 1871, Bd. i. S. 36; 1874, 
Bd. ii. S. 33. 
6 Inaug. Diss., Gottiugcn, 1868. 
7 Ber.d. dewtsch. chcm. Gesellsch., Berlin, 1872, Bd. v. S. 1075 ; 1874, Bd. vii. S. 570. 
8 Berl. klin. Wchnschr., 1885, Bd. xlvii. S. 761 ; C'ompt. rend. Acad. d. sc, Paris, 1888, 
tome cvi. p. 1176; and " Verhandl. d. Berl. physiol. Gesellsch.," in Arch. f. Physiol., 
Leipzig, 1890, S. 363. 
9 The secretion of the Har.Jerian gland of the orbit of rodents, though fatty in nature, is 
not formed by disintegration of cells ; Wendt, ' fjeber die Harder'sche Druse," Strassburg, 
1877 ; Kamocki, Biol. Centralbl., Erlangen, Bd. ii. S. 709. 
10 For anatomy, see Robby Kossmann, Ztsehr. f. wissensch. Zool., Leipzig, 1S71, Bd. 
xxi. S. 568. 
11 Ztsehr. f. physiol. Chem., Strassburg, Bd. iii. S. 225. 
13 Max Joseph, Arch. f. Physiol. Leipzig, 1891, S. 81. 
