376 Chittenden and Smith — Diastatic Action of Saliva. 



proteids, appears to still further increase diastatic action. Under 

 such conditions a minute trace of free acid appears to still further 

 increase the action. 



11. 0*003 per cent, free hydrochloric acid almost completely stops 

 the amylolytic action of ptyalin. The larger the amount of saturated 

 proteids the more pronounced becomes the retarding action of free 

 acids. 



12. The retarding ettects of the smaller percentages of free acid 

 are not due wholly to destruction of the ferment. Pronounced 

 destruction takes place with 0*()05-0*010 per cent, free hydrocldoric 

 acid. 



13. Proteid matter, in influencing the diastatic activity of salivary 

 ptyalin, acts not only by combining with acids and alkalies, but 

 apparently also by direct stimulation of the ferment. 



Sheffield Laboratory of Yale College, Jan., 1885. 



