846 THE SKIN AND ITS SECRETIONS. 



The preputial secretion, smegma prceputii, contains chiefly fat, also 

 cholesterin and ammonium soaps, which probably are produced from 

 decomposed urine. The hippuric acid, benzoic acid, and calcium oxalate 

 found in the smegma of the horse probably have the same origin. 



We may also consider as a preputial secretion the castoreum, which is secreted 

 by two peculiar glandular sacs, in the prepuce of the beaver. The castoreum is a 

 mixture of proteins, fats, resins, traces of phenol (volatile oil), and a non-nitrog- 

 enous body, castorin, crystallizing from alcohol in four-sided needles, insoluble 

 in cold water, but somewhat soluble in boiling water, and whose composition is 

 little known. 



In the secretion from the anal glands of the skunk, butyl mercaptan and alkyl 

 sulphides have been found (ALDRICH, E. BECKMANN *) 



Wool-fat, or the so-called fat-sweat of sheep, is a mixture of the secretion of 

 the sudoriparous and sebaceous glands. There is found in the watery extract a 

 large quantity of potassium which is combined with organic acid, volatile and non- 

 volatile fatty acids, benzoic acid, phenol-sulphuric acid, lactic acid, malic acid, 

 succinic acid, and others. The fat contains, among other bodies, abundant quan- 

 tities of ethers of fatty acids with cholesterin and isocholesterin. DARMSTADTER 

 and LIFSCHUTZ have found other alcohols in wool-fat besides myristic acid, also 

 two oxyfatty acids, lanoceric acid, CjoHeoCX, and lanopalmitic acid, Ci 6 H 32 03. 

 Isocholesterin, oxycholesterin and carnaubyl alcohol, C^ILgOH, are besides the 

 two last-mentioned acids, substances that are characteristic of wool-fat. Accord- 

 ing to ROHMANN 2 wool-fat contains a body lanocerin, which is the internal anhy- 

 dride of the above-mentioned lanoceric acid. 



The secretion of the coccygeal glands of ducks and geese contains a body similar 

 to casein, besides albumin, nuclein, lecithin, and fat, but no sugar (DE JONGE). 

 The chief constituent is octadecyl alcohol, CisHssO, which represents 40-45 per 

 cent of the ethereal extract (ROHMANN). The fatty acids are oleic acid, small 

 amounts of caprylic acid, palmitic acid, and stearic acid, and optical isomers of 

 lauric and myristic acid. The fatty acids are in great part combined with the 

 octadecylic alcohol, and this is probably formed by the reduction of stearic acid or 

 oelic acid. The secretion also contains a substance related to lanocerin which 

 ROHMANN calls pennacerin. Poisonous bodies have been found in the secretion 

 of the skin of the salamander and the toad, namely, samandarin (ZALESKI, FAUST) 

 and bufidin (JORNARA and CASALI), bufotalin and the disputed bodies bufonin 

 and bufotenin (FAUST, BERTRAND and PHISALIX 3 ). The active constituents in 

 the poison of the rattle-snake and cobra, the crotalotoxin and the ophiotoxin have 

 been isolated and studied by FAUST. 4 They are free from nitrogen and have a 

 similar composition, namely, CsJ^Oai and C34H 52 02o and are classified in the 

 pharmacological group of sapotoxins by FAUST. Thalassin is the crystalline body 

 discovered by RICHET 5 which is the poisonous constituent of the feelers of the 

 sea nettle. 



1 Aldrich, Journ. of Exp. Med., 1; Beckmann, Maly's Jahresber., 26, 566. 



2 Darmstader and Lifschiitz, Ber. d. d. Chem., Gesellsch., 29 and 31; Rohmann, 

 Hofmeister's Beitrage, 5, and Centralbl. f. Physiol., 19, 317. See also Unna, 1. c., 45; 

 and Lifschiitz and Unna, ibid., p. 234. 



3 De Jonge, Zeitschr. f. physiol. Chem., 3; Rohmann, 1. c.; Zaleski, Hoppe-Seyler's 

 Med.-chem. Untersuch., p. 85; Faust, Arch. f. exp. Path. u. Pharm., 41; Jornara and 

 Casali, Maly's Jahresbr., 3; Faust, Arch. f. exp. Path. u. Pharm., 47 and 49; Bertrand, 

 Compt. Rend., 135; Bertrand and Phisalix, ibid. 



4 Arch. f. exp. Path. u. Pharm., 56 and 64. 

 6 Pfluger's Arch., 108. 



