The ranch. [volume] (Seattle, Wash.) 1902-1914, 1907-12-01
HYDROCYANlC ACID GAS
AS a Fumigant for House and Mill
Nernin

ides are among the most powerful pol
sons known to SCIENCE. OF recent
years the cyanide of potash has come
into very general use among nursery
men as a destroyer of the notorious
San Jose scale-bug, and also for rid
ding green houses of aphides and
white flies. 1t is now coming into use
for destroying insects and other YER
min in dwellings, factories, mills, cars
and ships.
There are great many different
cyanides known to chemists, but for
practical use against insects and YER
min only cyanide of potash is recon-
mended. In purchasing cyanide OF
potash for use against insects and YER
min. ony the highest purity, or 49,
99.7 per cent grade should be accept
ed. The commercial grade of cyanide
of potash contains only about 46 per
cent of cyanogen and is on account of
its impurity practically worthless as
a fumigant, even when double or ire
BILE quantities are used. Cyanide OF
potash, SO to 99.7 per cent pure, is
the standard fumigant. 1t costs about
40 cents per pound or less in quaint
ties. Sulphuric acid, commercial
grade, costs about five cents per
pound.
The household vermin against which
cyanide of potash has been found sat
isfactory and very effective are as
follows:
Bed bug, cockroach, house fly, flea,
clothes moth, and ants of all kinds.
1t will also destroy rats and mice.
One fumigation will serve for all of
these pests, if they are present in a
building.
Against ants in nests the cyanide
May be used directly by making a
hole in the nest and pouring in halt
tea-spoonful of the powdered chemical
The insects in trying to remove and
carry out the particles in their mouths
will be killed. Against all other YER
min the cyanide is used in gaseous
form. For a room 10x10x10 feet, con
tanning 1000 cubic feet of space, the
following quantities must be used and
strictly in the proportions given:
Cyanide of potash, SO per cent, TO-
avoirdupois ounces; Sulphuric acid
20 fluid ounces.
Directions.
The above formula is for household
fumigation only. For nursery use the
acid may be increased to Is ounces
and the water to 80 ounces. Use a
deep glazed earthen vessel free from
cracks. A common water pitcher will
do. 1t should hold about fifty per cent
more than the amount of proposed di
luton, or in above case, about 48 fluid
ounces, or three pints. First place the
water in the pitcher and then very
slowly add the acid allowing this to
trickle down the side of the pitcher.
When all is in, shake the pitcher to
distribute the acid uniformly. Break
the cyanide into pieces not larger than
a hickory nut. Place the cyanide in
thin paper bag, such as grocers use
and drop the bag gently but quickly
into the calculated water. Then
promptly vacate the room. The fumes
of hydrocyanic acid are evolved rap
idly and are very dangerous, if breath
ed. One can, however, safely take one
half minute to get out of the room.
The fumes of hydrocyanic acid gas
are lighter than air and are very pene-
trating. Therefore in order to prevent
leakage of the gas, all windows and
chimney f1ues, key holes and door
cracks should have been previously
stuffed with moist paper or rags.
should be folded up so as to permit
the gas to get into cracks in the floor
and under the base-boards where car.
pet beetles, f1eas and reaches most
frequently hide. Carpets and other
articles of furniture need not be re-
moved from the room, as this gas
does them no injury. The room
should be locked and left closed over
night, or at least for six hours.