Chittenden and Smith — Diastatic Action of Saliva. 351 



tatic action is still sufficiently pronounced to convert 1*25 per cent, 

 starch into sugar daring 30 minutes warming at 40° C, 



The above results, indicative of such a mai'ked susceptibility of 

 the ferment in a dilute solution to the action of the alkali naturally 

 present in saliva, suggest the possibility of there being a direct con- 

 nection between the alkalinity of the natural secretion and its diastatic 

 power. While the results already given plainly indicate that very 

 slight changes in the alkalinity, everything else being equal, mate- 

 rially modify the diastatic power of the fluid ; still the amount of 

 ferment itself, as well as the amount of proteid matter, may vary in 

 different salivas so much as to counterbalance the direct influence of 

 changes in the alkalinity. 



This, the results of our experiments seem to indicate, as we have 

 been nnable to trace out any direct connection between the natural 

 variations of alkalinity and diastatic action.* 



Influence of diflereyit percentages of sodium carbonate on the dias- 

 tatic action oj saliva. 



« 

 In 1882, while studying the influence of peptones on the diastatic 



action of alkaline saliva,f data were then obtained showing a constant 

 diminution of diastatic action in the presence of the alkaline carbon- 

 ate : the conversion of starch into sugar being diminished in propor- 

 tion as the percentage of alkali was increased. The digestions at 40° 

 C, were then continued for 45 minutes and the ptyalin was present in 

 large amount, 25 of the 100 c.c. of digestive mixture being undiluted, 

 unneutralized saliva, thus making a very powerful diastatic fluid. 

 We give the data then obtained in the percentage of starch or glyco- 

 gen converted into sugar. 



a. Influence of 0'05 per cent, sodium carbonate. 



Saliva alone. Saliva + Na2Co3=0-05j^. Difference. 



Glycogen, 28-68 per cent. 20-20 per cent. 8-48 per cent. 



h. Influence of 0*15 per cent, sodium carbonate.:!^ 



Starch, 



Glycogen, 



* Compare Chittenden and Ely, Amer. Chem. Jour., iv, 329. 



f Chittenden and Ely, Amer. Chem. Jour., iv, 121. 



X The alkalinity is somewhat greater, owing to the unneutralized alkali of the saliva. 



Trans. Conn. Acad., Vol. VI. 44 March, 1885. 



