47 



Bisulphide of Carbon.—The simplest, most effective, and least 

 expensive remedy for all mill pests is bisulphide of carbon, a 

 very inflammable, volatile, foul-smelling liquid, as clear as water. 

 Its vapor is heavier than air, and will penetrate every crack and 

 •crevice in a mill or warehouse when used in sufficient quantities. 

 It can be thrown directly upon grain without iojuriug its edible 

 qualities, and will not affect iis vitality in the least. In mills it 

 can be used about the machinery, spouts, and elevators with per- 

 fect assurance that the manufactured products will not be dam- 

 aged. It is a powerful insecticide, the atmosphere produced by its 

 vapors being sure death to insects, as well as to rats and mice. I 

 know of no instance, however, where the slightest deleterious effect 

 has been realized by persons applying it in mills, although they 

 unavoidably inhale some of the fumes. 



The amount of liquid to be ueed depends (1) on the size of 

 the buildicg, ('2) on its tightness, and (8) on the magnitude of 

 the attack. Where the building is reasonably tight and but slightly 

 infested, one pound of bisulphide 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 ba doubled. 



A number of methods for the application of bisulphide of car- 

 bon have been suggested and tested, but the most effective man- 

 ner 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 num- 

 bers. Spraying or throwing the liquid broadcast into badly in- 

 fested 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 sweeper" 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 of 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 throughout the mill it should be 

 locked and kept closed undl the following 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 station- 

 ing a watchman without to prevent any one from entering the 

 building daring fumigation. 



