70 



G. MATTHEW FYFE. 



when the starch suspension is carefully added drop by drop, the contents of the 

 flask being shaken after each addition. A reflux condenser is then attached, 

 and the solution allowed to boil for about ten minutes. The resulting starch 

 solution is homogeneous and transparent, and allows of an intimate association 

 of the enzyme and substrate. It is not advisable to submit the small quantity 

 of starch to prolonged boiling, as is recommended by certain authors (Sherman, 

 Kendal and Clark, 1910), who, however, use a larger quantity of starch. 

 Table II shows how the diastatic index tends to be lowered when starch which 

 has been boiled for some time is used in the test. 



Table II. — Showing Variations in Diastatic Activity when 0"2 ex. Blood is 

 treated with Starch Solutions boiled for Different Lengths of Time. 



starch sokition boiled for — 



Case. 



1 



2 

 3 

 4 

 5 



The starch solution should be made with great care, and should be freshly 

 prepared every second or third day. No advantage seems to be gained in the 

 use of glycogen instead of starch (Table III). 



Table III. — Showing Comparative Activity of Diastase on Starch 



and Glycogen. 



Sugar formed. 



The diastatic figures of six normal subjects are given in Table IV. The 

 figure seems to vary in different individuals, the average being about 8 to 10 — 

 a figure somewhat lower than that of Myers and Killian (1917), and similar to 

 that of Stocks (1916). From data obtained it would seem that the normal 

 index should not exceed 15. 



Table IV. 



Case. 



K. 

 E. 

 A. 

 A. 

 C. 



K— 

 A— 

 T— 

 G— 

 R— 



W. S- 



-Showing the Diastatic Activity of Blood in Normal Cases. 



Age. 



30 

 22 

 33 

 34 

 30 

 30 



