38 
air for several minutes without continuous pumping. The stopcock at a regu- 
lates or prevents the escape of air, aS may be desired. B is an ordinary 
2-quart bottle fitted at bi: with a tight stopper of good length, having two open- 
ings, through which the inlet and outlet pipes pass. These pipes may be of 
glass or metal and should be as large as can be used. ‘The inlet pipe, b:, reaches 
nearly to the bottom of the bottle and is provided at the lower end with a 
perforated metal cap as large as will pass through the neck of the bottle. 
This allows the escape of the air in small bubbles and insures rapid evaporation. 
The outlet pipe, 0s, reaches only through the stopper. Upon the outside of 
the bottle is pasted a paper marked with 1l-ounce graduations. OC is a piece 
of ordinary 32-inch iron gas pipe about 33 feet long, but this may be any desired 
length. It is closed and roundly pointed at the tip, and for about 15 to 18 
inches of its length provided with small perforations pointing in all directions 
to give free escape to the vapor into all parts of the sack of seed at once. 
The connections may be of rubber tubing, but as little rubber as possible 
should be used for this apparatus, as it is affected by the vapor of the bisulphid, 
and the couplings will have to be frequently replaced. This, however, will not 
be a considerable item of expense. With the apparatus just described one 
operator would be able to accomplish the entire work of disinfection. The 
amount of carbon bisulphid recommended is about 1 ounce for each 3-bushel 
sack. It is safe to say that this can be secured for less than 1 cent per ounce 
when purchased in 25 or 50 pound lots, making the cost of bisulphid not over 
1 cent per sack. As it requires but from two to three minutes to vaporize 1 
ounce of the liquid in the manner described, the expense for labor in applica- 
tion would not amount to one-half a cent per sack. Fumigation with carbon 
bisulphid can therefore be effectively made at the slight expense of from 1 to 
14 cents per 100-pound sack. 
Application of the bisulphid in this manner reduces the elements of danger to 
a minimum, as the vapor is almost wholly confined and the slight quantity escap- 
ing, mixed with the open air, would not be in either inflammable or explosive © 
proportions. It has been determined that the slight trace of bisulphid vapor in 
the air would not injure the operator in the slightest degree. The sacks should 
be left in the box for forty hours after the gas is injected. 
RELATION OF MEANS OF CONTROLLING THE BOLL WEEVIL TO 
THE CONTROL OF OTHER INSECTS. 
The cotton bollworm.—The most important insect enemy of cotton 
in the United States, aside from the boll weevil, is the bollworm. 
This pest has existed in this country for many years and frequently 
reduces the crop very considerably. The annual damage to cotton 
in the United States has been conservatively estimated at over 
$8,000,000. In addition to the injury to cotton this insect is a very 
important enemy of corn, tomato, okra, cowpeas, and some other 
crops. Careful studies of the bollworm were conducted by Mr. A. L. 
Quaintance, of the Bureau of Entomology, in connection with large- 
scale field experiments in many localities. The conclusions drawn 
from this practical work were that the essential steps to be resorted 
to in the control of the boll weevil are exactly the ones that should 
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