52 



Scientific Proceedings (36). 



calcium) metabolism after thyroid-parathyroidectomy similar results 

 ought to follow Eck fistula or ligation of the hepatic artery. 



33 (443) 



The relation of ptyalin concentration to the diet and to the 

 rate of salivary secretion. 



By A. J. CARLSON and A. L. CRITTENDEN. 



\_From the Hull Physiological Laboratory of the University of 



Chicago^ 



1. The relation of ptyalin concefitralion to the diet. 



a. In Man. — 1. In the fall of 1908 the diastatic power of the 

 parotid saliva of three individuals (A. J. C, A. L. C, C. C.) desig- 

 nated for convenience as A, B, and C, was compared daily for a 

 period of ten days. The saliva of A was uniformly slightly 

 stronger than that of B, and considerably stronger than that of C. 

 At the end of the ten-day period B and Cwere put on an exclu- 

 sive vegetarian diet, that is, meat was excluded and the carbo- 

 hydrates greatly increased, for ten days, while A continued on the 

 ordinary mixed diet. The diastatic power of the parotid salivas 

 was tested daily and there was no increase in B and C as checked 

 against A. 



2. The diastatic power of the parotid saliva of a man who for 

 four years had been a consistent vegetarian was checked (for seven 

 days) against that that of A and B. It was uniformly less than A 

 and practically the same as B. 



3. The parotid or mixed saliva of a boy of 14 years, a "con- 

 genital " vegetarian, never eating meat, was checked against the 

 corresponding salivas of A and B. It showed uniformly less dia- 

 static power than A, and about the same as B. 



Thus, contrary to Nielson's results, there is no evidence that 

 in man even years of exclusion of meats and greatly increased carbo- 

 hydrates in the food will appreciably increase the ptyalin concentra- 

 tion i7i the saliva. 



b. In Other Mammals. — It is conceivable that while shorter 

 periods of meat exclusion and carbohydrate increase in the diet of 

 man may not effect an increase in the ptyalin, generations of vege- 

 tarianism might be effective. This could be tested on the saliva of 



