162 Drs. S. Martin and D. Williams. [June 12, 



and that to which 3 per cent, of taurocholate had been added con- 

 tained T2424 per cent, dextrose. 



Glycocholic Acid. The addition of pure glyeocholic acid in the 

 proportion of 0'5 per cent, arrested digestion of starch by pancreatin ; 

 probably because of the acidity of the mixture. 



Glycocholate of Soda. A weighed quantity of pure glyeocholic acid 

 was dissolved in distilled water and neutralised with anhydrous 

 carbonate of sodium. Four vessels, each containing an equal quantity 

 of distilled water in which 1 per cent, of starch had been boiled, were 

 taken : to B 1 per cent, of glyeocholic acid by weight neutralised 

 with Na. 2 C0 3 , and to C 2 per cent, of glyeocholic acid neutralised by 

 the same salt were added. Equal quantities of pancreatin were added 

 to A, B, and C ; D being reserved as a control. The mixtures were 

 digested for seven minutes at 37 to 38 C. The colour struck with 

 with iodine solution by C was then red, by B purple-red, and by A 

 purple. Digestion was then stopped by boiling and the quantity of 

 dextrose estimated by Fehling's method : A contained 0'357 per cent., 

 B 0'476 per cent., C O588 per cent. 



Glycocoll, Leucin, and Tyrosin. Glyeocholic acid is formed by the 

 conjunction of glycocoll and cholalic acid, glycocoll itself being amido- 

 acetic acid. Leucin and tyrosin, the end-products of pancreatic 

 digestion, are also amido-acids, leucin being amido-caproic acid, and 

 tyrosin, oxyphenyl-amido-propionic acid. Glycocoll was found to be 

 without any effect upon the pancreatic digestion of starch. 



Leucin appeared to interfere to some extent with pancreatic diges- 

 tion of starch ; thus, in one experiment, in which 0'5 per cent, of pure 

 lencin was added to a starch mixture and digested with pancreatin 

 for twelve minutes, the amount of sugar estimated as dextrose was 

 0'526 per cent., while the amount in a similar mixture digested for 

 the same time without leucin was 0'645 per cent. 



Tyrosin also appeared to interfere slightly with pancreatic digestion 

 of starch. Thus, in one experiment three vessels were taken, each, 

 containing 100 c.c. of distilled water in which 1 gram of starch bad 

 been boiled; to flask B 0'05 gram of pure tyrosin and to flask C O'l 

 gram tyrosin were added ; the three mixtures A, to which no tyrosin 

 was added, B, and C were then digested for nine minutes with equal 

 quantities of pancreatin. At the end of five minutes the colour 

 struck with iodine solution varied, A giving a reddish-purple, C and 

 D a bluish-purple ; at the end of eight minutes the colour with A 

 was almost pure red, with B and C still a bluish-purple. The 

 quantity of sugar estimated as dextrose by Fehling's method was as 

 follows: A 0'383 per cent., B 0'345 per cent., and C 0'333 per 

 cent. 



Carbonate of Sodium. Carbonate of sodium, when present in the 

 proportion of 0'25 per cent, and over, retards pancreatic digestion of 



