CHEMICAL BASIS OF THE ANIMAL J!U)V. Ill 



of the animal body. It is however a substance of considerable 

 interest and importance, not merely on account of its chemieal 

 relationship to kreatin (see below) but as having been employed 

 in a well-known series of experiments intended to elucidate tin- 

 probable mode of formation of urea in the body. It was stated 

 that when sarkosin is administered to an animal in quantities 

 siu-h that tin- nitrogen given as sarkosin is equal to the daily 

 output of nitrogen as urea by the animal, the urea disappears 

 from the urine and is replaced by a new substance. 1 The latter 

 appeared to be a compound of sarkosin and carbamic acid, known 

 generally by the name of methyl-hydantoic acid, NH, . CO . N 

 (CH,) . CH . COOH. This substance may be regarded as arising 

 from the union of one molecule of sarkosin with one of carbamic 

 acid and elimination of one molecule of water, or as being urea in 

 whieh two atoms of hydrogen are replaced by methyl and a resi- 

 due of acetic acid respectively : NH S . CO . N (CH 8 ) (CH 2 . COOH). 

 The conclusions drawn from these observations were that just as 

 methyl-hydantoic acid is supposedly formed by the union of 

 sarkosin with carbamic acid and subsequent dehydration, so also 

 would urea be formed if, instead of sarkosin, ammonia were pres- 

 ent, tn unite with the carbamic acid, form ammonium carbainate 

 (NH 4 . NH 2 . CO 2 ) and by loss of water yield urea. Subsequent 

 repetition of these ingenious experiments has shown that they 

 are in no way conclusive, for in most cases the sarkosin is largely 

 excreted in an unaltered condition, methyl-hydantoic acid being 

 formed in very minute quantities if at all. 2 It is further interest- 

 in;: to note that the purely chemical reactions which most readily 

 yield methyl-hydantoic acid out of the body, involve the inter- 

 action of sarkosin with cyanic compounds such as ammonium or 

 j'ota ium cyanate. 3 Moreover it has been shown that at the 

 temperature of the body sarkosin and urea in solution do not 

 yi<-ld methyl-hydantoic acid, although they do in ]>resen 

 baryta, especially when boiled. 4 These facts show that Schultzen's 

 experiments do not strongly favour the carbamic-acid origin of 

 1 1 re; i ; they further show that the methyl-hydantoic acid is prob- 

 ably not Conned by a direct union of >arko>in and urea, ami are, 

 from a purely chemical point of view, rather in favour of a cyanic 

 in of urea. 



4. Taurin. C,H 7 NSO,. [CH, (NH,) . CH, (SO, . OH) ]. Amido- 

 ethylsulphonic acid. 



Isethionic acid, CH, (OH) . CH, . SO, (< >II ). like glycolic acid, 



1 Srlnilt/.on, Ber. d. d. rh, ,. /;. Y | *:_. S. 578. 



Baumaim u. von Mi-rin^. //-/. lsT.\ S. :>*4 K. Salkowski, Ibid. S. 6.38. 

 A1-... /.'. I. /-Ai/MV. di.m. IM. iv (issn), sn. .V,, Inl. Hut nee also Sdiiff.-r, //.//. 

 .:,: ; 15.1. MI. (1883), S 



8 Baumaim u. HopiKvSeyler, Ber. d. d. cheat. Getell. 1874, S. 34. Salkowski, 

 Ibid. S. Mr,. 



4 Hauiiiuiiii u. Hoppe-Seyler, lc. fit. Itaumaou, Ibid. S. -' 



