58 
The amount of liquid to he used depends (1) on the size of 
the building, (2) on its tightness, and (3) on the magnitude of 
the attack. Where the building is reasonably tight and but 
slightly infested, one pound of bisulfide is sufficient for every 
thousand cubic feet of air space. If it is somewhat open or 
badly infested the amount should be doubled. When applied to 
bins containing stored grain, one pound of the liquid to every 
hundred bushels of grain is commonly used; but if the insects 
are very abundant the amount of bisulphide should be doubled. 
A number of methods for application of bisulfide of carbon 
have been suggested and tested, but the most effective manner 
of applying it in mills consists in simply pouring the liquid into 
shallow dishes, such as soup plates, or pans, and distributing 
them about the building. Bits of cotton-waste saturated with 
the liquid should also be thrust into spouts elevator legs, 
machines and other places where the pests usually congregate 
in great numbers. Spraying or throwing the liquid broadcast 
into badly infested corners, on machines, and other pieces of 
apparatus where the pests are particularly abundant, has been 
attended with very good results. 
Saturday afternoon is the best time for fumigating a mill. 
After sweeping it from top to bottom, using a “steam sweoper” 
where it is practicable, all fires about the premises should be 
extinguished and the mill closed as tightly as possible. The 
dishes and cotton-waste should be previously distributed, so 
that there will be no unnecessary delay in the application of 
the foul-smelling fluid. The distribution of these vessels must 
of course depend, as already stated, upon the condition ot the 
mill and the severity of the attack. It is best to begin with the 
lowest story and work up, as the operators can then keep above 
the settling gas. When the bisulphide has been applied through- 
out the mill it should be locked and kept closed until the fol- 
lowing Monday morning. All windows and doors should 
then be thrown wide open and the building allowed to air an 
hour before any fire is started. Where the building is large and 
a great quantity of bisulphide has been used, it would be wise 
to observe the extra precaution of stationing a watchman with- 
out to prevent any one from entering the building during fumi- 
gation. 
As a guide to millers who may use this method for exter- 
minating insect pests in mills, I will quote several letters from 
practical millers who have used bisulphide of carbon success- 
fully. The superintendent of a large Pennsylvania milling com- 
pany, whose name is withheld by request, under date of July 
12, 1895, wrote me the following letter, which is a valuable con- 
tribution to this subject, and should be read by every wide- 
awake miller and grain dealer: 
“We have delayed answering your valued favor of May last 
until we were able to report the result of our efforts to destroy 
the weevils in our mill. Following in the line of your advice, 
we ran our stock down and thoroughly renovated our mill from 
top to bottom, cleaning all reels and purifiers. We then fumi- 
gated the whole mill with bisulphide of carbon. We distributed 
300 soup plates about half filled with bisulfide through the mill, 
and saturated balls of cotton with the same material and placed 
them in all the reels and purifiers. This we did on Saturday 
night, and closed the mill tight and left the weevils to their 
destruction. 
