COCKROACHES. 13 
Borax.—Powdered borax enters into the composition of many of 
the so-called roach powders. This substance may be used either 
pure as a poison or repellent or mixed with some other substance to 
render it attractive to the insects. Several correspondents have 
reported great success from the use of a mixture consisting of 1 part 
powdered borax to 3 parts of finely pulverized chocolate, this mixture 
to be freely sprinkled about the infested premises. 
Pyrethrum.—Another common remedy consists in the liberal use 
of pyrethrum powder or buhach. This is at best but a temporary 
expedient, but if persisted in considerable relief will be gained. To 
be at all effective it must be fresh and liberally applied. The roaches 
are often paralyzed by it rather than killed outright, and the morning 
after the application all paralyzed and dead roaches should be swept 
up and burned. 
Sulphur.—F lowers of sulphur dusted about where roaches abound 
has also proved, on the authority of Mr. A. I. Mudd, of this depart- 
ment, very effective as a repellent. 
Phosphorus.—Of the proprietary substances, perhaps one of the 
oldest and most efficient is a form of phosphorus paste. It consists 
of sweetened flour paste containing 1 to 2 per cent of phosphorus, and 
may be distributed on bits of paper or cardboard placed in the run- 
ways of the roaches. It has been used very successfully in the offices 
of this department to free desks from Croton bugs, numbers of dead 
insects being found in the drawers every day during the time the 
poison was kept about. It also has some repellent value. 
FUMIGANTS. 
Hydrocyanic-acid gas.—Hydrocyanic-acid gas fumigation is a thor- 
oughly effective means of ridding premises of roaches, but involves 
considerable cost, difficulty of application, and the necessity of taking 
extreme precautions on account of the deadly nature of the gas to 
higher animals, including human beings. <A special publication, 
which may be had on application, has been issued by the Department 
of Agriculture giving the steps of the process in detail. 
Carbon bisulphid.—Wherever roaches infest small rooms or apart- 
ments which may be sealed up nearly air-tight, and also on shipboard, 
the roach nuisance can be greatly abated by the proper use of carbon 
bisulphid. This substance, distributed about a pantry or room in 
open vessels, will evaporate, and, if used at the rate of 1 pound to 
every 1,000 cubic feet of room space, will destroy roaches. Unless 
the room can be very tightly sealed up, however, the vapor dissipates 
so rapidly that its effect will be lost before the roaches are killed. 
The hatches of ships, especially of smaller coasting vessels, may be 
battened down, a very liberal application of carbon bisulphid having 
been previously made throughout the interior. If left for 24 hours 
