C. REID. 



161 



alternatively at the middle of this period. As it is impossible to estimate 

 actually the amount of diastase in the urine and blood, the ratio of the amount 

 of starch converted by 0*2 c.c. urine to the amount of sugar formed by 0'2 c.c. 

 blood has been taken as the diastatic concentration factor. 



number of milligrammes of starch converted by 0'2 c.c. urine 

 number of milligrammes of sugar formed by 0'2 c.c. blood 

 U.D. X 0-2 



D.C.F. = 



U.D. X 0-2 

 B.D. 



X 100. 



The diastatic concentration factor was found to vary considerably through- 

 out the 24 hours. The results in Table VII from two subjects — typical of a 

 series of at least half-a-dozen — show the sort of variations obtained in a 

 number of individuals. 



Case A 



Case B 



Time. 



Table VII. — Breakfast 8 a.m. 



B.D. U.D. D.C.F. 



From the point of view of convenience it was decided to carry out a 

 number of investigations on healthy adults, and to examine the diastatic 

 activity of the blood at two hours and four hours or alternatively at three 

 hours after the first meal of the day, and to examine the diastatic activity of 

 the urine secreted during the second two-hourly period after the same meal. 



Table VIII gives the diastatic concentration figures obtained in young 

 adults and in children of fifteen and under by the above method. 



A factor which must be considered in cases giving low urinary diastatic 

 figures, apart from those due to polyuria, is that of the blood-diastase figure. 



Case 6 has a low U.D. and moderately low B.D., but the lowness of the 

 D.C.F. is due to the presence of a certain amount of diuresis due to excite- 

 ment. Case 14, on the other hand, shows low figures for the U.D. and B.D., 

 but the D.C.F. in the absence of polyuria is within normal limits. 



