CHEMICAL BASIS OF THE ANIMAL BODY. 203 



urine by methods similar to those used for the preparation of 

 indoxyl-enlphuric acid. 



( )ur knowledge of tin- quantitative formation of skatol'in the 

 alimentary canal and of its relationship ti tin- simultaneous pro- 

 duction of indol is far less complete than is that respecting the 

 latter substance. Notwithstanding the close chemical relation- 

 ship of the two it appears that their physiological behaviour is 

 markedly ditleivnt. In the tirst place it seems that the absorp- 

 tion of skatol is less complete than that of indol. since it pre- 

 ponderates in the normal fares: 1 in accordance with this but 

 little of its ethereal sulphate is found normally in urine.- Fur- 

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

 sulphates of the urine may be converted into the ethereal com- 

 pound with indoxyl, when skatol (synthetically prepared) is 

 similarly employed a large part reappears in the t';eces ; and 

 although at tirst the ethereal sulphates are increased, they sub- 

 sequently diminish even with continued injection of skatol, and 

 are stated to finally disappear, [ndoxyl-snlphuric acid may be 

 regarded as a urinary chromogen, since it yields a pigment, indigo, 

 .idational decomposition; so also may skatoxyl-sulphuric 

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

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

 not so directly proportional t" the amount of skatoxyl-sulphuric 

 acid as it is to the similar compound of indoxyl when indol is 

 administered. It has been suggested that a large part of the 

 skatolic chromogen exists as a compound of skatoxyl and glycu- 

 runic acid." When Jaffa's test (see p. 200) 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 mat- 

 ter thus obtained is probably formed from the skatoxyl (not 

 known in the free state), and by reduction may be made to 

 yield skatol. 



"1 li;i- recently IM-I-H ile-erilieil :is iirrinu' in a vegetal"! 



sue, namely tin- wood <>f an Ka>t Indian tree. Celt is ret imlosa.* 



nt frm the faecen of the dog. 

 - Hi.' rhii-f n-i-iinl >( its ..<< nrn iu-e is in a cae of diabetes mellitus with 



clisiiirUnri-. Otin. PlluiirrV A-l, IM \XMII !--).> 



M. '..//I. 15,1. xii dssH). - I 10 \ .-iinilar c.iin|Miun.J ..f 



iml'i\\ 1 \\iili ^hiiir"iiic :niil ha* been tlcscrilx-.l. S<-liinio(lcberK. .1 /'nth. 



n. rtinrw. lid . "xiv. (issi). g j,l,'i.- tin- lilt-ratlin- >f this >ub*ttnce 



>.ilk-.w^ki. Zr. /: i>h> t il. Chftn. IM MM S 117. i\. (I --4'. Mi I 

 Dniistrui. rimrm. .11. V,,l \i\ (1889), \> IDlo />,, ,1 ,1 . ,>, CeteU. 

 (Referate), IM \\n (isv.i,.s. ui Proc. Roy. Soc. Vol M.M (1889), p. all. 



