Chittenden and Smith — Diastatic Action of Saliva. 867 



Series XVIII. 



40 c.c. filtered saliva were neutralized and diluted to 200 c.c. ; 10 

 c.c. of this diluted fluid were used in each experiment. 



A standard solution of peptone saturated with hydrochloric acid 

 was also prepared. 



The following percentages of peptone and combined acid were 

 contained in the different digestive mixtures of 100 c.c. 



12 3 4 5 6 7 



Peptone, O-OI^ 0-020jg 0-040^ 0060^ 0-080^ 



Combined HCl, O-OOOG;?* 0-00057<g 0-00115^ 0-0023^ 000345^ 0-0046<J 



Following are the results of the digestions : 



It is to be noticed, first, that in this geries of experiments the 

 peptones, being completely saturated with acid, are present in much 

 smaller percentages proportionally than the combined acid is, and the 

 effect produced is a diminished diastatic action in the case of Nos. 6 

 and 7, in the presence of an amount of combined acid which, in the 

 case of the proteids naturally present in saliva, has no retarding 

 action whatever, but on the contrary a stimulating action. The 

 addition of a larger amount of peptone to Nos. 5, 6 and 7, for exam- 

 ple, the percentage of acid remaining the same, tends to bring up 

 the diastatic action very decidedly. 



It would appear from these results, moreover, assuming that the 

 combining power of peptone is the same as the proteids present 

 in saliva, that the presence of say 0*003 per cent, combined HCl in 

 the form of saturated acid-peptone has a retarding action, while the 

 same percentage of combined HCl in the form of saturated salivary 

 proteids, has, in the case of saliva of the same dilution, a decided 

 stimulating action. At the same time it is to be remembered that 

 when acid is added to saliva some considerable acid may be used by 

 the inorganic salts with formation of acid phosphates, for example. 

 These results, moreover, indicate that such is doubtless the case. 

 Increasing the percentage of peptone to say 1 per cent, admits of 

 the addition of larger amounts of hydrochloric acid, without partic- 



* To saturate the proteids naturally present in the saliva. 

 Trans. Conn. Acad., Vol. VI. 46 March, 1885. 



