4.J4 <J aY.lAV \! <>/ /'//YS/of <n,y 



chooses to assert that the proteids of the tissues f.ill 

 single descent nearly to the stage of urea, there i 

 hiile real evidence to contradict him. \Vli.ii is certain i 

 ili;ii from in"--! ir.-.nr, ihc nitrogen docs not pass oni chiefly / 

 ihc form of nrca, that it appears in the urine mainly as urea, an 

 thai tin- change is effected to a large extent, but not ru//r/,v/v, 

 in the liver. Among Us precursors are probably ammonia 

 pound . 



Uric acid, like mea, i, <.. p.u .if. -,| doni (he Mood by tin- 

 kidneys, nol to any appreciable extent formed in them, in 

 birds, and often in man, it can be detected in normal blood, 

 It is present in increased amount in the blood an<! transtida 

 tioni "l gouty patients, in whose joints and ear-< artila^c \\ 

 <h. it ("i nr. < <>n< ri lions, ' Chalk-stones ' may contain m<ne 

 ilian hall ilnn weight of sodium urate. The spleen yie.l 

 small jii.iiitity of uric acid, which maybe increased 1>\ -Mow- 

 ing air through a mixture of > plenic pulp and blood. 



As to the source of the uric acid, it is well established ihai in ihe 

 l,n,| ii i . formed I". Mi in. in ihc md prodm Is ol proteid metabolism 



find 1 1 "i 1 1 mil I, -i n i>iii|i<.iiiid . .-in- 1 lie ii del i va lives. 1 n Ihc iu;imm;il, 



(he i.d ing of food rich in nucleated cells, and therefore in nu 



juotenl . :ind inn !< ins (lliynur; ; ' |>;nn leas, ;ind IH-II in ; 



01 nl I i in Ii 111 mi' ! in liases* (l.irl)i;-'s meal ' ,ha< I ), illi n 



the quantity of uric acid in ih-- urine. The increase i i - M pan due 



to the piodm lion ! inn :K id I i the inn lein siilr.lam es ( |. ronie). 



I'.iil iln-, i . n.. i MM . <.;!. e (,l the uric .n id, sim e exlr;iets ol the 

 thviini', i'l.nnl (iini.-iining only trace's ol nUCleitlS or nuelen 



< ;iUSe when injc( led, ;i < li.il n l.-n ,ln Iln n .1 e in ihc tlfJC .n id 

 ;i n lion, jii-.l ;i . llie entiie i'J;ind does when laki n l.y ihe nmtiili. 



And during the period "i increased nitrogen excretion caused l>\ a 



meal containing |.n>iiid ihe inereai.e in lln- inn- ;KI.| oeeuis p.n 



m nl. niv in ihe in.nrs immcdiai- ly i.lhi\viii:- ilu; ingcstion ! ihe food, 

 and does not last so long as the increase in ih- urea. Now, ihe 

 nuclcins of the fool are comparatively imie affected during the 

 earlier stages of digestion (Hopkins and Hope). We may com ludi-, 

 thereioic, ihai m ihe mammal, as well as in ihe i.ini, .1 portion of 



the mi< .1- id, although < - il.nnly a l.n sinallei poition in the mammal, 

 is < 1 1 rived In nu I .odie', ol In a I han I he nuclei n substances ol I lie I 

 1 h;il r, to say, I lot n I he nin lein si ib -lances ol ihe tissues and liom 

 Ihe proleids ol hoih loo. I and tissues. 



* Nin Ir.ns, ill. i hid (on lilucnls ol 1 1 if n IK lei >l cells, air cdinpoiinds 

 i,l prolrid v illi inn lri ;n ids 'I Iir nut lci< Hi id ., ..I win. Ii al l.-.r.l Imir 

 ; ,ir known, arc < nmpnnnd . "I an a< id and one '.I ilir inn lein kr.rs or 

 alloxan Ixxlic ,, sin h .1 adcnin, jMiamn, x.mtlim, liy|)o\antliin. 



a 



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