50 
acetate and 5 cc. of clear lipase solution. These solutions were allowed 
to stand at 20° C. for one and two hours, respectively, when they 
were titrated with X 50 sodium hydroxide, with the folio wins - results: 
Time. 
Cubic centimeters. X 50 
sodium hydroxide re- 
quired. 
Per cent of hydrolysis. 
Acetate. 
Cyanace- 
tate. 
Acetate. 
Cyanace- 
tate. 
1 hour 
0.8 
0.6 
3.2 
2.4 
2 hours 
1.05 
. 85 
4.2 
3.4 
With another specimen of lipase, the other conditions of the experi- 
ment remaining the same, the following- results were obtained: 
Time. 
Cubic centimeters. X.5C 1 
sodium hydroxide re- 
quired. 
Per cent of hydrolysis. 
Acetate. 
Cyanace- 
tate. 
I 
Acetate. 
Cyanace- 
tate. 
2 hours 
4 hours _ 
0. 95 
1.30 
0.65 
.70 ! 
3.8 
5. 2 
2.6 
2.8 
With still another specimen of lipase, the other conditions the same 
as those given in the above, the following results were obtained : 
Time. 
Cubic centimeters. X 50 t 
sodium hydroxide re- 
quired. 
Per cent of hydrolysis. 
Acetate. 
Cyanace- 
tate. 
Acetate. Cvanace- 
17 hours 
2. 10 
1.00 
8. 4 4. 0 
It will be seen from these results that the introduction of a cyano- 
gen radical into the molecule of an ethereal salt does not greatly alter 
its conduct toward lipase. At most, the rate of hydrolysis by lipase is 
diminished one-half. It seems, further, that for shorter intervals the 
rate of hydrolysis of these two ethereal salts by lipase are more nearly 
equal than they are for longer intervals. The probable explanation 
of this is that, so far as the esters themselves are concerned, both are 
probably hydrolyzed by lipase with nearly equal rapidity. The cyan- 
acetic acid, however, being a stronger acid than acetic and probably 
more toxic in other respects, doubtless inhibits the activity of lipase to 
