THEIR CHEMICAL CONSTITUENTS. 383 



to the hairless sebaceous follicles of the prepuce and the glans 

 penis. It was obtained from the ethereal extract by extraction 

 with water, and yielded, with sulphuric acid and sugar, the most 

 beautiful biliary reaction ; that this could not be fat, is sufficently 

 obvious from its solubility, as well as from the rapidity with which 

 the reaction ensued ; but whether the substance is identical with 

 any of the products of decomposition of the biliary acids, is a 

 question that must be decided by further investigations. 



The resinous constituents of castoreum have been already men- 

 tioned. Wohler* has shown that they contain carbolic acid, or oxide 

 of phenyl (C 12 H 6 O 2 ), which may be detected by the blue colour 

 it imparts to a pine-shaving saturated with hydrochloric (Runge) 

 or nitric acid (Laurent). Since the resinous constituents of cas- 

 toreum coincide in a remarkable manner with those of hyraceum 

 (which, according to my investigations, can only be the dried 

 intestinal excrement of Hyrax capensis), and since phenylic acid 

 occurs in both these substances, it seems most probable that they are 

 not products of the metamorphosis of tissue, or that they are any 

 peculiar secretion, but merely derivatives of the resinous sub- 

 stances conveyed in the intestinal canal of the animal with its food. 



Benzole acid has been detected in castoreum by Saugier, 

 Brandes, Batka, and Riegel ; from certain experiments which I 

 made on the contents of fresh pouches, I think it probable that 

 hippuric acid is originally contained in this substance. 



I found benzole acid in the preputial smegma of a horse. 



It is very doubtful whether uric acid occurs in castoreum, 

 although Brandes believes that he has found it. 



In the preputial secretion of herbivorous animals, there is 

 little phosphate of lime, which seems replaced by carbonate of 

 lime; this, at all events, is very abundant in castoreum. This 

 salt may be easily recognised, by observing under the microscope 

 the considerable development of gas which the residue, insoluble 

 in ether, alcohol, and water, yields on the addition of acetic acid, 

 and by noting the considerable turbidity that is induced in the 

 fluid which is thus obtained, by the addition of oxalate of 

 ammonia. 



In fresh castoreum we can recognise with the microscope the 

 well known crystals of sulphate of lime, and in the preputial 

 smegma of the horse, the octohedral forms of oxalate of lime. The 

 presence of both salts may be readily confirmed by a few micro- 

 chemical experiments. 



Ann. de Ch. u. Pharm. Bd. 49, S. 360, and Bd. 65, S. 342. 



