TEMPERATURE AND TOXIC ACTION. 
CHARLES BROOKS. 
(WITH THIRTY-THREE CHARTS) 
THE purpose of these experiments, the results of which are pre- 
sented in this paper, was to determine what might be the modifying 
effect of temperature on the toxic properties of certain chemicals as 
shown by the effect of these substances on germination and growth 
in certain fungi. Since chemical processes as well as plant activities 
are influenced by temperature, it was thought that additional knowl- 
edge in regard to the nature of the physiological action of poisons 
might be obtained by comparing their effects at the optimum tem- 
perature for germination and growth of the plant with results secured 
under otherwise similar conditions, but at temperatures below and 
above that which is most favorable for the development of the particu- 
lar plant. 
So far as the writer has been able to learn, the problem of toxic 
action has never been carefully investigated from this standpoint. It 
is well known that temperature is an important factor in the pro- 
cesses of plant and animal life, and that changes in temperature may 
often serve as a stimulus to reproduction, germination, and develop- 
ment. It has also been shown that the response of an organism to 
certain stimuli may vary with the temperature, and some data have 
been reported which indicate that this is true when the stimulus is 
of a chemical nature. THreLe (1) found that the maximum tem- 
perature for the growth of Penicillium glaucum on grape sugat lies 
at 31° C., on glycerin at 36° C., on salts of formic acid at 35° C. 
NAGEtt (2) reported that bacteria were killed at 30 or 110° C. accord- 
ing to the character of the nutrient medium, but his conclusions seem 
to be based upon results obtained from impure cultures. H2EIDER (3) 
found that the toxic action of certain chemicals upon the spores of 
Bacillus anthracis increases with a rise of temperature. PasTEUR (4) 
found that bacteria were more resistant to heat in alkaline than in 
acid milk; but Conn (5) and BREFELD (6) observed no such increased 
resistance in alkaline solutions, RicHET (7) has reported that with 
359] [Botanical Gazette, vol. 42 _ 
