CI1KMICAL BASIS OF T1IK AM MAI. 1;<>1>Y. 



I'.eitij.-r's 'liiiiK.r paitcn-at icti> ' contains in addition t> 



tin- cn/\ nifs I.., tli Iriicin an<l kyraein together with prtt-i.i 



actively protfolyt it- that th- >niall amount re<|unvd to \ idd an acti\- 

 dii;..-tive solution introduce^ an amount \ impurities which inav \- 

 in-^lected in many ca-i->. The al>\ ( - impurities may !> lar^. i 



rid of by precipitating oul the .-n/vines \\ith aid. h.. 1 u desorib 



Although trvpsin exhibits its liydrolytic jxiwers to tin- 

 advantage in presence "f an alkali, its activity is scared y~so 



ly related to_th_e alkali as is that of in-psiit to dilute hy<]i - 

 c-hloric acid. Thus it will digest pruti-ids, although much luTiic 

 slowly in a m-utral solutimi and i-vt-n in jin-scncc of dilute ('01- 



' hydrochloric acid, Imt tin- slight. -! exoen < 1 p. c. ) of the 

 arid d.--n'.y- it. 1 In connection \vith these >tat-nn-ni> it nm-t 

 hi\vi-vi-r In- Imriif in mind that pr<>t-ids ] ia vc tin- JM.W.T *>f readily 

 (uiiiliiniii^ with acids, hence the addition of say -1 j. :. of hydm- 

 <'lil"ric acid to a digestive mixture dues nt imply that th. 

 then '1 p. c. of free acid in the solution.- 



This comparative independence of tryptic activity in its rela- 

 ti"iis t<> the reaction of the digestive mixture i< dmilitless f rm- 

 siderable physiological .significance. The reacticm of the contents 

 of the small intestine is very variable. The chyme as diseh 

 from the stomach is of course acid, and this aridity is lar-.'ly 

 diminished by the advent of the stronulv alkaline bile and pan- 

 crejitic jniei-. so that the reaction may become alkaline within a 

 short distance of the pylorus. On the other band the alkaline 

 ;.>n mavjtot be at all appreciable until the lower end of tin* 



ine is reaclied, and fn-nuently, at least in dogs, the reacti.m 

 ntly aci<TTriroii^T7(iut, whether they are fed on prot.-ids or on 



a mixture of carliohyTTrates and fat. :; The acidity in the latter 



[fl not -urj. rising bearing in mind the ivadim-ss with which 



the earbohy.lrat.-- undergo a lactic tci mentation, e-pe.-ially inside 



the intestin.-. and it mi^ht therefore have been abnormal in tin- 



do-j whose food does not normally contain carbohydrates. On 



the other hand in man. living on a mixed diet, the possibility of 



a laetie fermentation is always present. 4 It is impossible to makf 



jj'U-ral statement as t" the reaction of ihe contents ^>f_^' 



small intestine ; it varies at different times, ami drjNMuls upon the 



!,!... Virrliow's Arek. IM. X^MN (ItST), > n" Ili-i-li-iiliain. 1'ti 

 Arrfi. 15.1 \ '( " /- / ''"I "I 



v l.il|illnTl,'iT (Sw.'.,|i.|| I XIII. 



.', '/A f. i>hi/niiJ. Chnn. Hi I. i. I!-" 



;../. H' ... 1880 N... :l. v. .1. Vi-l.l.-n. />'> ' i H.I. \\n 



. . S. |C,. Cf. I.an-l.'v :in,| ' ./ V.,1 n 



iimi.lt-Miilli.-im. Arek. I. /Vi./W. .Inhrg. 1879. S. .19. Ciwh. /'.'/ IH80.8. 

 123. F,-:i. .//. /'/, 



mil. n- . 



niiivi-f Miilk-Miu'.irl int.. H'l " I I'- 



ll' t 



