1890.] On the Influence of Bile on Pancreatic Digestion. 161 



and the four vessels kept at a temperature of 40 C. At the end of 

 seven minutes there was a marked difference between A and B aiid 

 C in their reaction to a solution of iodine : A gave a deep blue- 

 purple, B and C a red-purple. At the end of thirteen minutes C 

 gave a faint red colour, B a red-purple, while A gave the same purple 

 colour as after seven minutes. No change occurred in D. The 

 solutions were then boiled and the amount of sugar in A, B, and C 

 estimated as dextrose by Fehling's method : A contained 0'526 per 

 cent., B (H>49 per cent., and C 0*675 per cent. 



The experiment was varied by using an active powdered pig's pan- 

 creatin, manufactured by Savory and Moore. Four vessels were used, 

 each containing 50 c.c. of distilled water in which 1 gram of starch 

 had been boiled. To B 1 per cent, and to C 2 per cent, of ox bile salts 

 were added and dissolved. To A, B, and C, pancreatin 0'15 gram was 

 added ; D was reserved as a control. The mixture was digested for 

 seven minutes in a water-bath at 45 C. ; at the end of this time A 

 struck a blue-purple colour with iodine, B a dirty red-purple, and C 

 gave only a trace of red colour. The amount of dextrose was esti- 

 mated by Fehling's method with the following result : A contained 

 0-3846 per cent,, B 0-71429 per cent., and C 0'833 per cent. 



Ox bile salts and human bile nave, therefore, the same property as 

 pig's bile and bile salts ; they augment the amylolytic action of the 

 pancreatic amylopsin on starch. 



Bile salts consist of a mixture, in varying proportions, of the 

 alkaline (chiefly sodium) salts of taurocholic and glycocholic acid. In 

 human bile, and that of most mammals, as well as in birds and 

 amphibians, taurocholates are most abundant; in the pig,glycocholates. 

 Experiments were therefore made separately with glycocholate and 

 taurocholate of soda. 



Taurocholate of Soda. The salt used was a commercial product 

 and contained some bile pigment. Four vessels, each containing 

 100 c.c. of distilled water in which 2 per cent, of starch had been 

 boiled, were taken : to A 1 gram, to B 2 grams, to C 3 grams, and to 

 D 4 grams of the taurocholate were added ; 0'8 gram pancreatin was 

 then introduced into each, and the mixture digested at a temperature 

 of 37 for a quarter of an hour. Tested by the colour struck with 

 solution of iodine, D had been more changed than C, C than B, and 

 B than A. The amount of dextrose estimated by Fehling's method 

 was A 0-8G9 per cent., B TO per cent., C T05 per cent., and D I'll 

 per cent. In another experiment the effect of 1 and of 3 per cent, of 

 the taurocholate were contrasted with each other and with the effect 

 of pancreatin alone. Digestion was continued for ten minutes at 

 a temperature of 40 41 C., and the mixture then boiled ; that con- 

 taining no taurocholate contained 0*909 per cent, dextrose, that con- 

 taining 1 per cent, of tanrocholate contained Till per cent, dextrose, 



