CHAPTER XVII 
FUMIGANTS 
Iw general, fumigation is available for killing insects only when the 
plants or substances treated are in an inclosed space. This is for the 
reason that the various gases which are the active killing agents in 
any fumigation must be confined to be effective. 
Fumigation is commonly used in greenhouses, in the treatment of 
pests infesting stored or manufactured products, and in the treatment 
of nursery stock suspected of infestation with San José scale. The 
methods employed and the strengths of material used vary with these 
different classes of work. The general manner of using the chemicals, 
and the principles involved, are similar. 
Carbon Bisulphide 
Carbon bisulphide_ . 3 1 pound to each 100 cubic feet 
This is the material ordinarily used for Killing pests of stored and 
manufactured products, except in grain elevators where the risk of 
accidental fire is considered too great. It is a clear, heavy liquid, 
with a strong and disagreeable odor. On exposure to air, it evapo- 
rates rapidly, giving off a gas that is heavier than air, and therefore 
diffuses down rather than up. 
Allow 1 pound of carbon bisulphide for each 100 cubic feet of 
space in the fumigating chamber. Or, if grain is being fumigated, 
allow 1 pound of the liquid to each 100 bushels of grain. In small 
quantities this is about equivalent to 2 drams to the bushel. 
This is the dosage at ordinary temperatures of 60° to 70° Fahren- 
heit. At much lower temperatures a heavier dose will be required, 
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