25 
after twenty hours and the tobacco powder, after being freed as much 
as possible from the adhering alcohol by pressure between filter paper, 
was extracted with 20 cc. water for three hours at the ordinary tem- | 
perature. The filtrate, as well as the undried residue, yielded almost 
exactly as much oxygen in fifteen minutes as was obtained in the con- 
trol case, showing that alcohol does not act injuriously on the enzym, 
at least not within a short time. 
A concentrated cold-prepared extract of sweated tobacco was mixed 
with one-tenth of its volume of alcohol and left in a filled, well-stop- 
pered flask for five days in a dark box at a temperature of from 15° to 
18° C. There was no indication of bacterial growth. Twenty ce. 
of this liquid gave in ten minutes 37 cc. oxygen, while in the contro! 
case 50 cc. were originally obtained. The action of catalase on hydro- 
gen peroxid is not influenced by the presence of small quantities of 
alcohol, but larger quantities—above 30 per cent—exert a retarding 
influence, especially noticeable when the amount of catalase present is 
but small. 
The action of boiling absolute alcohol is of some interest. One gram 
of sweated tobacco was kept for half a minute in boiling absolute 
alcohol and then, after the removal of most of the alcohol by pressure 
between filter paper, extracted with cold water. Upon addition of 
10 cc. hydrogen peroxid to the filtrate, as well as to the residue sus- 
pended in 20 cc. water, the following results were obtained: 
Cubic centimeters of oxygen developed in twenty minutes. 
By a-cata- | By B-cata- 
lase. lase. 
REESE TEN Soe mg een ee A ere ae ee Re RL Se ee Me TS Dan RE a 2 55 3 
MOODEREE CEE i eth Bek oe et yy See oe ede ees a 6 Cyne Ned A er El eg aig 70 20 
The remarkable fact that boiling absolute alcohol does not instantly 
kill the enzym is probably due in part to the fact that all enzyms resist 
a higher temperature in the absence of water than when dissolved 
in water, and also to the fact that alcohol boils at a comparatively low 
temperature. 
BEHAVIOR TOWARD CHLOROFORM. 
A concentrated aqueous extraet of sweated tobacco was left with some 
chloroform for five days in a dark box. Then, after the evaporation 
of the chloroform at the ordinary temperature, 20 cc. of the liquid 
were mixed with 6 cc. of hydrogen peroxid. In ten minutes the vol- 
ume of oxygen obtained was: 
eee eee le oe oi ee a 
COO AB ep os LS ee ee nl ee nner ee 54 
‘The control test was made with an equal amount of the same extract before the 
experiment was begun... 
