CHEMICAL BASIS OF T1IK ANIMAL BODY. 



hippuric acid arises from the ben/oie and allied constituents of 

 tin- vegetable part of the food, and probably not an inconsiderable 

 amount from the putrefactive products of tin- proteids in the ali- 

 mentary canal; in accordance with tin- it i- found that disinfec- 

 tion of tin- alimentary canal in do^s with calomel diminishes the 

 outjnit of the acid. 1 Ty rosin, notwithstanding its aromatic con- 

 stitution, does iiot give rise to hippuric acid when administered to 

 nan. 1 



The classical researches of Bunge and Sc hmiedeberg 3 li;i\ 

 shown that the >yiithetic. production of hippuric acid by the 

 union of beuzoic acid and ulycin takes place chietly in the kid- 

 ney of carnivora (dogs). In herbivora (rabbits) it appears that 

 a considerable formation of hippuric acid may be observed on the 

 -:ion of benzoic acid even after exclusion nf the kidneys. 4 and 

 the same is the case with frogs. Pathological observation.- on 

 man seem to indicate that in them the kidneys play at least some 

 part in the synthetic production of hippurir acid from benzoic. 6 

 When benzoic acid is administered to birds it reappears in the ex- 

 creta as ornithuric acid: the latter when boiled with hydrochloric 

 acid splits up into benzoic acid and ornithin. the latter having the 

 composition of diamido-valerianic acid. 6 



a Tyrosin. c,H n N() :; . [( HI . C 6 H 4 . CH 2 . CH . (NH,) . CooH]. 

 >xyphenyl-a-amidopropionic acid. 



The earlier work on the synthesis of ty rosin indicated the prob- 

 able presence in its molecule of some aromatic (phenyl) radicle. 

 The more recent successful synthesis by the action of nitrous acid 

 mi para-amidophenyl alanin " has confirmed this view and defi- 

 nitely established its constitution. 8 It always accnnij'anies leiicin. 

 though less in amount, as a product of the pancreatic di^otiun of 

 proteids, l>ut not of gelatin, also as a 'product of their putrefactive 

 decomposition as well as of the action of boiling mineral acid* and 

 alkalis. It is also perhaps found normally in small quantities in 

 the pancreas and its secretion and in the splr.-n. and tracet have 



I n described as obtained from various tis>ue- ,,t the body' 1 l - 



is normally absent in urine, but. makes its appearance together with 

 leucin in this excretion in several diseased conditions of the liver, 

 notably acute yellow atrophy, also in pbo.p horns poisoning ; there 



>. ,,/,,/giol. Cl,.m. H,|. \. (1886), S 



../. IM \i (i-- 

 /t, r,nh. . /'/,.!,// . H.I. vi. (in:r,). s 



H.I. M- . See lo II. 'fTiii.'iiin. A //.../. 15,1 M -339. 



\V S:il..iii,.n. '/.< i- /./../"/. <'!> i. H-l. in. (!><:'.). S 365. 



.lanrMrl.l ii. s,t..kvi. .1 >. i . Pod 1871 8 268. 



Jnfl ,/. ,!,.,. GtM& i 



M.ii.in i- a :uiii.l..jiP.pi..iii.- :i.'i-l : CII, . CH i v 'H 



:.-niin-\iT M. Lii'p.. /' '/. '/ -lirm. Gttflt. 1882, S. 1544. I. i. !,;_< Anna!. 

 1M -.'M 1889 8. 161 



9 v. Gortip-Itaancz, fahrb. d. phytiol. Ckem. Bd. i\ I-:-, j,;, U 



