27 
success. Winnowing weeviled grain is also an excellent preliminary 
treatment. 
Raising the temperature of the grain in closed retorts or revolving 
cylinders to 130° to 150° F. will kill the inclosed insects if continued 
for from three to five hours, but is apt to injure the germ, and is not 
advised in case of seed stock. The simplest, cheapest, and most effec- 
tual remedy is the use of bisulphide of carbon. 
BISULPHIDE OF CARBON. 
This is a colorless liquid with very offensive odor, which, however, 
passes off completely in a short time. It readily volatilizes and the 
vapor, which is very deadly to insect life, is heavier than air and settles 
and fills any compartment or bin in the top of which the liquid is placed. 
It may be distributed in shallow dishes or tins or in saturated waste on 
the top of grain in bins, and the gas will settle and permeate through- 
out the mass of the grain. In large bins, to hasten and equalize the 
operation, it is well to put a quantity of the bisulphide in the center of 
the grain by thrusting in balls of cotton or waste tied to a stick and satu- 
rated with the liquid, or by means of a gas pipe loosely plugged at one 
end, down which the liquid may be poured and the plug then loosened 
with arod. Prof. H. E. Weed reports that in Mississippi the chemical 
is commonly poured directly onto the grain. In moderately tight bins 
no further precaution than to close them well need be taken, but in open 
bins it will be necessary to cover them over with a blanket to prevent 
the too rapid dissipation of the vapor. The bins or buildings should 
be kept closed from twenty-four to thirty six hours, after which a 
thorough airing should be given them. 
Limited quantities at a time may often be advantageously subjected 
to treatment in small bins before being placed for long storage in large 
masses, and especially whenever there is danger of introducing infested 
grain. 
The bisulphide is applied at the rate of 1 pound to the ton of grain, 
or a pound to a cubie space 10 feet on a side. 
In the case of mills, elevators, or larger granaries the application may 
be best made on Saturday night, leaving the building closed over Sun- 
day, with a watchman without to see that no one enters, and to guard 
against fire. The bisulphide should be first distributed in the lower 
story, working upward to avoid the settling vapor, using the substance 
very freely, in waste or dishes, at all points of infestation and over bins 
throughout the building. 
This insecticide may also be used in other stored products, as pease, 
beans, etc., and very satisfactorily where the infested material can be 
inclosed in a tight can, chest, or closet for treatment. 
The bisulphide costs, in 50-pound cans, 10 cents per pound, and in 
small quantities, of druggists, 25 to 35 cents per pound. 
Caution.—The bisulphide may be more freely employed with milling 
