CIIKMK'AL I'.ASIS OF Till: ANIMAL 1;<>I>V. 185 



South America, an infu>im i the h-a\e- ,,i" / /' x,', x -. n, 



kola-nuts u.-ed a- food MI ( '-nt nil Africa (tin- I'ruit of .S/r//</ 

 (ti-innliKitn), in Smith African hush-tea.' ami in many other plants 

 from \\hich st iinnlat ini; beverage- an- "kained liy infusion. 1 Apart 

 from tin- clOM chemical relationshipof tin- alkaloida] principles of the 

 abo\ c plant> t. tin- nitro<4eiiou- cr\-talline c\t ract i\ e- ' of muscle-, 

 it is inteiv-t iiiu t.i notice further that they s.-.-m to bear tin- .-aim- 

 j^eiieral relationship to the or^anism> in which they respect ively occur. 

 There can I't- luit little ilmilit that the xanthin h.<lie> (and uric aci<l) 

 an- typically prmluct> i tin- i|n\\nuanl e\cret i.inary nit m^en-nis 

 inetaKc'lisin of animals. The alkaloidal principles of plants, in this 

 case theohroinin ami caffeine, may lie >imilarly re^irde.! a^ BXCn- 

 tionary pmilm-ts ami are hence I'miml collected in t ho^,. part- of the 

 plant uliich are more immediately or ultimately cast off, \\7.. the 

 leaves, -.-, d-. and hark. The facts already stated render the consump- 

 tion of theolu-omin and caffeine in -..me form or other by practically 

 the \\hole human race !.->> surprising than it mi^ht at first si^ht 

 appear. Their universal use also indicate- that they >upply -ome 

 distinct \\ant of the economy which cannot a- yet he explained purely 

 with reference to their relationship to the nitrogenous extract! 

 animal ti--iie.-. hut rather to the physiological effect their invest ion 

 produces. In moderate do-e- they exert an a^iveahh- >timulatin^ 

 action wherehy the >ensati<uis of fatigue and drou-ine-- are removed, 

 the body bein^ thus enabled to exert it.-elf with le-s sense of effort 



and less initial stimulus, and the mind is more acti\e. clearsighted 



and insistent to the depre--ing effects of unpleasant influences. There 

 i- no evidence, as was at one time assumed, that they act in any uay 



by reducing the activity of nitrogenous metabolism. 1 In the case of 



and cho,-,, late we have to deal not merely with the stimulating 

 - of the theohroinin they contain, but al-o with the fact that 

 they are of extreme nutrient value, owin^ to the lar-je amount of fats 

 ("i<> p.c. ). proteid- (1 p.c.). and carbohydrate- \\hich enter into their 

 comjiosition. The comparative physiological action of xanthin. theo- 

 broinin. caffeine, and some of their derivatives have recently been 



studied by Pilehne.* 



TIIK AROMATIC SERIES. 



1 . Benzole acid C,H 6 . COOH. 



This is not found a- a normal ron-i it uent of the body. When 

 urs in (chielly herbivorous) urine its presence i* usually dun 

 rinentative decoiiip..-iti..n of hipj.uric acid whereby beii/oie 

 acid and u'lyi'in ( ijlycocollj are 1'i.rined. 



C II .00, Nil OH "<>H +11 " 



= C.H,.COOH. + CH,(MI . C I 



.lliil Chlirrli, ('/,. nfroinmnH lit'-, 1HHO. p. UT 



I HH-hon. I 1 -- 



.1 --A. /: l'h>iu>l. ./ '/i. II. 



rixirm. H.I. xv. (188LM. S. .'J, ami <-f. |{.,^!,ar!i. 1'llu- ; 



