Chittenden and Smith — Diastatic Action of Saliva. 363 



20 c.c. A, 

 21-9 B, 



Increase, 

 5 c.c. A, 

 5-5 B, 



starch converted. 

 33.85 per cent. 

 35-22 



1'37 per cent. 

 24-69 per cent. 



27-58 



Increase, 2-89 per cent. 



Here the same results are to be seen as in the preceding exj^eri- 

 ment, although the amount of proteid matter is inuch less. In both 

 series of experiments it is to be noticed that as the percentage of com- 

 bined acid is diminished the difference between the diastatic activity 

 of the neutral solution and the corresponding acid solution is increased, 

 at the same time it is to be seen that in the first series of experiments 

 where the percentage of proteid matter is larger there is a greater in- 

 crease in the conversion of starch with the 23*4 c.c. of acid-reacting 

 saliva than with the 21 "9 c.c. of the acid-reacting fluid of the second 

 series of experiments with its smaller percentage of proteid matter. 



In the last series of experiments where 21-9 c.c. of J3 are used the 

 amount of combined acid in the digestive mixture is but 0*00094 per 

 cent. HCl, so that where the smaller amounts of acid-reacting saliva are 

 used the percentage amount of combined acid is very small indeed. 



Increasing the amount of saliva used and thereby the percentage 

 of acidTproteid matter brought us finally to a point where the acid- 

 proteid matter failed to stimulate the diastatic action of the ferment 

 and even began to show a tendency to retard its action. The follow- 

 ing series of experiments, using saliva wholly undiluted, illustrates 



this point. 



Series XVI. 



100 c.c. of filtered saliva were neutralized requiring 32 c.c. 0*2 per 

 cent. HCl=.4. 



52-8 c.c. ^4=40 c.c. of the original saliva required 12"15 c.c. 0-1 

 per cent. HCl to combine with the proteids, making saliva H ; the 

 fluid was distinctly acid to litmus and contained 0-0187 per cent, 

 combined acid. Three digestions were made with both A and JS, 

 using quantities of the fluids equal to 20, 10 and 5 c.c. respectively 

 of the original saliva. 



26-4 c.c. A, 

 32-48 B, 

 13-2 c.c. A, 

 16-24 B, 



60 c.c. .4, 

 8-12 B, 



Wt. Cu in one-eighth. 

 0-1083 gram. 

 0-1065 



0-1024 gram. 

 0-1087 



00948 gram. 

 0-1031 



Total amt. sugar. 

 0-4408 gram. 

 0-4336 



0-4168 gram. 

 0-4424 



0-3864 gram. 

 0-4192 



