COMPOSITION OF HUMAN MIXED SALIVA. 265 



were analyzed every hour or two throughout the day. Fol- 

 lowing are the results obtained : 



Here, as in the preceding experiments, there is noticeable 

 the same diminution of amylolytic power, alkalinity, and con- 

 tent of solid matter, etc., in the mixed saliva secreted directly 

 after the morning meal. Of special significance, however, is 

 the marked variation in the values throughout the day, 

 thereby suggesting the existence of a normal curve of secre- 

 tion. Thus, after the morning meal the saliva shows the 

 effect of the stimulation by its lower content of solids etc. 

 Soon after, however, there is an upward tendency ; the curve 

 rises, and amylolytic power is increased as well as the alka- 

 linity, together with the total solids and organic matter. The 

 inorganic salts, on the other hand, still remain low. Towards 

 noon time, amylolytic power sinks very greatly, and there is 

 a corresponding drop in the proportion of organic solids, 

 although the alkalinity and inorganic salts still remain fairly 

 high. After this, amylolytic power gradually rises, reaching 

 the maximum again at 5 p. M. with a corresponding rise in 

 alkalinity, total solids, etc. Supper at 7 P. M. apparently 

 causes a slight fall hi amylolytic power, together with a fall 



