180 FUMIGATION METHODS 
the influence of the gas, and should not remain more 
than two or three hours in gas of sufficient strength to 
destroy animal life. 
Dry seeds.—Only a few experiments have been 
performed along this line, but probably a sufficient 
number to determine the point in question, viz., 
whether dry seeds treated with hydrocyanic acid gas 
retain enough of the gas to make them injurious to 
animal life. Grain was subjected to gas of different 
strengths, and for longer or shorter periods of time, 
varying from one to sixty days. Grains thus treated 
were from time to time fed to mice that had been 
caught without injury, and placed in glass cages so 
that they could be observed constantly. The cages 
were provided with an abundant supply of air and 
water, and kept at ordinary normal temperature of the 
laboratory where the mice had been living previous to 
the beginning of the experiment. Occasionally the 
mice began eating the grains as soon as they were 
placed within reach, but, as a rule, several minutes to 
several hours elapsed between the time the grains were 
taken from the hydrocyanic acid gas and the time they 
were eaten by the mice, thus giving time for any gas 
that remained in contact with the seed or that had 
penetrated the seed-coat to escape into the amosphere. 
In one instance, for example, a mouse was fed one 
dozen kernels of corn and three dozen grains of wheat 
that had been for four and one-fourth days in an at- 
mosphere containing gas from one gramme of potas- 
sium cyanide per cubic foot. The mouse began eating 
the grain at once, and at the end of twenty-four hours 
had eaten the whole of five grains of corn and had 
