204 SKATOL. 



leaves the body in the urine as a potassium salt of the above acid 1 . 

 This salt may be isolated from urine by methods similar to those used 

 for the preparation of indoxyl-sulphuric acid. 



Our knowledge of the quantitative formation of skatol in the 

 alimentary canal and of its relationship to the simultaneous production 

 of indol is far less complete than is that respecting the latter substance. 

 Notwithstanding the close chemical relationship of the two it appears 

 that their physiological behaviour is markedly different. In the first 

 place it seems that the absorption of skatol is less complete than that 

 of indol since it preponderates in the normal faeces 2 : in accordance 

 with this but little of its ethereal sulphate is found normally in urine 3 . 

 Further, whereas by the ingestion of indol nearly the whole of the 

 sulphates of the urine may be converted into the ethereal compound 

 with indoxyl, when skatol (synthetically prepared) is similarly employed 

 a large part reappears in the fseces ; and although at first the ethereal 

 sulphates are increased they subsequently dimmish even with continued 

 injection of skatol and are stated to finally disappear. Indoxyl- 

 sulphuric acid may be regarded as a urinary chromogen since it yields 

 a pigment, indigo, by oxidational decomposition ; so also may skatoxyl- 

 sulphuric acid, but it is found that the amount of pigment-forming 

 material specifically present in the urine of a dog fed with skatol is 

 not so directly proportional to the amount of skatoxyl-sulphuric acid 

 as it is to the similar compound of indoxyl when indol is admin- 

 istered. It has been suggested that a large part of the skatolic 

 chromogen exists as a compound of skatoxyl and glycuronic acid 4 . 

 When Jafie's test (see p. 201) for urinary indican is applied to urine 

 which contains skatoxyl compounds the results obtained are as follows. 

 The urine turns dark red or violet on the addition of hydrochloric acid, 

 bright crimson on the addition of nitric acid, and a similar colour is 

 obtained if it is warmed with hydrochloric acid and ferric chloride. 

 The colouring matter thus obtained is probably formed from the 

 skatoxyl (not known in the free state), and by reduction may be made 

 to yield skatol. 



Skatol has recently been described as occurring in a vegetable tissue, namely the 

 wood of an East Indian tree, Celtis reticulosa 5 . 



1 Brieger, Zt. f. physiol. Chem. Bd. iv. (1880), S. 414. Baumann u. Brieger, 

 Ibid. Bd. in. (1879), S. 255. G. Hoppe-Seyler, Ibid. Bd. vn. (1883), S. 423. 



2 It is absent from the fseces of the dog. 



3 The chief record of its occurrence is in a case of diabetes mellitus with 

 gastric disturbance. Otto, Pfliiger's Arch. Bd. xxxm. (1884), S. 607. 



4 Mester, Zt. f. physiol. Chem. Bd. xn. (1888), S. 130. A similar compound of 

 indoxyl with glycuronic acid has been described. Schmiedeberg, Arch. f. exp. Path. 

 u. Pharm. Bd. xiv. (1881), S. 306. To complete the literature of this substance 

 see E. Salkowski, Zt. f. physiol. Chem. Bd. vm. S. 417; ix. (1884), Sn. 8, 23. 



5 Dunstan, Pharm. Jl. Vol. xix. (1889), p. 1010. Ber. d. d. chem. Gesell. 

 (Beferate), Bd. xxn. (1889), S. 441. Proc. Roy. Soc. Vol. XLVI. (1889), p. 211. 



