110 STORED GRAIN AND FLOUR. 
of the grain. The liquid rapidly volatilizes, and, being heavier than 
air, descends and permeates the mass of grain, killing all insects, as 
well as rats or mice, which it may contain. 
‘‘The bisulphide is usually applied in tight bins at the rate of a 
pound to a pound and a half to the ton of grain, and in more open 
bins a larger quantity is used. . . . Bins may be made nearly 
air-tight by a covering of cloths or blankets. Oilcloth and painted 
canvas are excellent for this purpose. 
** Mills and other buildings, when found to be infested throughout, 
may be thoroughly fumigated and rid of insects by a liberal use of the 
same chemical.” 
Mr. Chittenden here notes, amongst other things, that the doors 
and windows should be closed as tightly as possible, and a watchman 
stationed without to prevent anyone from entering the building, and 
he also gives the very necessary caution that the building should 
be thoroughly aired early in the morning before the return of the 
workmen. 
To continue the extract from Mr. Chittenden’s paper :— 
‘It is best to begin in the lowest story and work up, in order to 
escape the settling gas. . . . The bisulphide is usually evaporated 
in vessels, one-fourth or one-half of a pound in each. 
“Infested grain is generally subjected to the bisulphide treatment 
for twenty-four hours, but may be exposed much longer without 
harming it for milling purposes. If not exposed for more than 
thirty-six hours its germinating power will be in no wise impaired. 
In badly infested buildings it is customary to repeat this treatment 
about every six weelis in warm weather.”—(F. H. C.) 
The bisulphide treatment has long been considered as one of the 
most valuable methods of disinfection both in Canada and the United 
States, but I have hesitated to bring it forward on account of the 
danger both to human health and even life, and also the great danger 
to property consequent on its extreme inflammability, unless used with 
both care and knowledge. 
How far its use may vitiate an insurance I do not know, but it 
will ignite in temperature heated up to a certain point even in the 
absence of light from fire, lamp, &c., and even the lght of a cigar 
will or may cause ignition; and in experiments of my own I have 
seen a specimen dressed with the fluid ignite merely from exposure to 
the sun’s rays in the open air. 
One other point remains to be noticed, and that is infestation by 
means of screenings from foul corn, sold cheap, carrying infestation 
around in the neighbourhood of mills. These, according to their 
nature,—as the small broken bits of straw sold for pigs’ bedding, the 
mixture of small shrunken Wheat, with broken grain and chaff, sold 
