New York AGRICULTURAL EXPERIMENT STATION. [65 
Bisulphide of carbon has been partially described in article on 
cabbage aphis. It is a colorless liquid with an offensive smell. 
It is heavier than water and the fumes are heavier than air. If 
applied directly to plants it evaporates so rapidly that it may 
freeze them. Bisulphide of carbon can be purchased at eight 
cents per pound in barrel quantities or at 10 cents per pound in 
50 pound cans. 
Tobacco may be used as a powder, as a liquid or in the form of 
fumes. As previously stated it is a more active insecticide than 
- most of the “insect powders.” 
Hot water is a useful insecticide, on a small scale, when it can 
be applied directly to the insects. | 
Omitting a few special cases insects which feed on plants may 
be divided into two groups, based upon their method of feeding, 
viz., biting or gnawing insects and sucking or pumping insects. 
For the first group, or biting insects, only the first class of 
remedies are practical. For the second group or suctorial insects 
only the second class of insecticides can be used. 
For a more complete description of insecticides, their prepara- 
tion and use, farmers will find “The Farmer’s Bulletin,” No. 19, 
issued by the United States Department of Agriculture, a very 
practical work. 
