1918] 
BONNS—ETHERIZATION AND ENZYME ACTIVITY 271 
diluted with an equal volume of distilled water previously 
cooled to low temperature, and both solutions packed in ice 
until ready for use. The only modifications of Appleman's 
apparatus were the use of test-tubes of about 100 се. capacity 
in place of the bottles used by him for gas generation, and 
the substitution of a small graduated burette of 25 ec. capacity 
for the separatory funnel serving as the reservoir of hydrogen 
peroxide. 
In determining oxygen values, 1 or 5 cc. of enzyme extract 
and 5 ec. of fresh solution of commercial hydrogen peroxide 
(3 per cent H202) were allowed to react; readings were made 
every 30 seconds, allowing 15 seconds for gas generation in 
the chamber and the same time for displacement of the water 
in the burettes. Before admitting the peroxide solution the 
enzyme extraet previously placed in the gas chamber was 
brought to 20? C., and this temperature was maintained 
throughout the series by keeping the chambers in the con- 
stant temperature bath. During periods of gas generation 
and displacement the test-tubes were constantly shaken by 
hand in as uniform a manner as possible. 
RESULTS AND DISCUSSION 
In the tables and discussion of results the following system 
of notation is employed for brevity: 
Series А 1.—Enzyme dispersion from tissues extracted im- 
mediately after etherization,+ substrate. 
Series A 2.—Same dispersion, autoclaved before adding to 
substrate. 
Series B 1.—Enzyme dispersion from controls extracted 
simultaneously with enzynie of А 1,+ sub- 
strate. 
Series В 2.—Same dispersion, autoclaved before adding to 
substrate. 
Series C 1.—Enzyme dispersion from tissues extracted 18 
hours after etherization,+ substrate. 
Series C 2.—Same dispersion, autoclaved before adding to 
substrate. 
