



1901 | EFFECT OF HYDROCYANIC ACID GAS 263 
influence of hydrocyanic acid gas at the rate of one gram or 
less of potassium cyanid per cubic foot without entirely destroy- 
ing the ability of the seeds to germinate. 
Dry seeds subjected to the influence of hydrocyanic acid gas 
derived from one gram of potassium cyanid per cubic foot will 
lose their germinating power at the expiration of eight months, 
while the same seeds subjected to the gas from one third of a 
gram of potassium cyanid per cubic foot will retain their vitality 
until the expiration of twelve months. 
The exposure of dry seeds for from fifteen to sixty days to 
the influence of hydrocyanic acid gas from one third to one 
gram of potassium cyanid per cubic foot will hasten germination 
and accelerate the growth of the resulting seedlings. Although 
the acceleration continues for several days, it does not seem to 
be of sufficient duration and degree to be of any practical value. 
Damp seeds are much more sensitive to the influence of 
hydrocyanic acid gas than dry seeds. 
Seeds soaked twenty-four hours or more will not germinate 
in gas stronger than 0.0038" of potassium cyanid per cubic foot, 
whereas, if the seeds are soaked but twelve hours, they are able 
to germinate in an atmosphere containing hydrocyanic acid gas 
from 0.050™ of potassium cyanid per cubic foot, and in much 
less time than when soaked for twenty-four hours. 
Seeds soaked thirty-six hours will germinate much more 
readily than when soaked only twenty-four hours, but will not 
germinate in a stronger atmosphere of hydrocyanic acid gas than 
0.003*" of potassium cyanid per cubic foot. 
Seeds soaked for twenty-four hours and then left for seven 
days in an atmosphere of hydrocyanic acid gas will remain 
inactive while in the gas, and from seven to twelve days after 
removal, but will eventually germinate to some extent if the 
strength of gas used does not exceed 0.050™ of potassium cya- 
nid per cubic foot, 2. ¢., hydrocyanic acid gas is capable of hold- 
ing seeds in an inactive state for two weeks or longer without 
destroying their vitality, even when the conditions are otherwise 
favorable for germination. 
