1918] 
BONNS—ETHERIZATION AND ENZYME ACTIVITY 263 
desired temperature and subjected to a preliminary heating 
for 24 hours to insure a uniform heat throughout the tissues. 
The jars to be etherized were then fitted tightly with rubber 
stoppers, through each of which passed a piece of glass tub- 
ing of about 5 mm. diameter and 8 em. in length. The upper 
end of this tube was fitted with rubber tubing and a screw 
clamp. From the part below the stopper a small basket of 
copper gauze containing a tuft of cotton was suspended by 
copper wires. Before etherization the stoppers were forced 
in as tightly as possible, and the juncture of stopper and jar, 
as well as the surface of the former where the tube entered, 
was thoroughly sealed with a liquid mixture of equal parts 
of beeswax and paraffin. The calculated ether dose was 
dropped with a pipette through the tube on the cotton below, 
and the screw clamp immediately and very securely tight- 
ened. That no ether escaped during the experiment, even 
with the pressure resulting from the temperatures used, was 
evident upon opening the clamp at the end of the exposure. 
The control jars were also fitted with rubber stoppers, but 
were not sealed. In every case the dosage used per jar was 
1 cc. of Merck’s ether for anaesthesia. Johannsen (706) in 
his forcing experiments recommends 0.4 gm. per liter volume, 
and the amount used in the following work approximates this 
very closely on the basis of 1800 cc. volume per jar. 
Upon removal from the jars at the close of this part of an 
experiment, the plant extracts, whether studied as such or 
used for enzyme extraction, were made in the following man- 
ner: The bulbs or corms were rapidly grated on a fine-meshed, 
flat grater into a large porcelain dish and transferred in a 
manner as nearly quantitative as possible with a minimum 
amount of distilled water to water-tight, tin cylinders 15 cm. 
high and 6.5 em. in diameter, with tightly fitting covers, which 
were at once placed in a freezing mixture of ice and salt. At 
the end of a sufficient time the frozen cylindrical mass was 
removed from each tin and again grated. The resulting mass 
of snow was then transferred to large glass jars for extrac- 
tion. In the case of the preliminary experiments with tulips, 
where the extracts were studied directly, extraction was made 
