INSECTICIDES THAT KILL OK KEPEL BY BEING 
INHALED. 
CARBON BISULPHIDE. 
This is an extremely volatile liquid having a very disa- 
greeable odor and its use must be attended with a good deal 
of caution as it is explosive when mixed with air and 
brought in contact with fire. It can be used to destroy any 
insect that can be got into a tight receptacle as a box, jar or 
room. It is also destructive to root-infesting insects and 
ants in hills when injected into the ground in proximity to 
the insects. When employed for the destruction of insects 
in tight receptacles, use about one quart to every i,ooo cubic 
feet of space and continue the treatment for 24 hours at 
least. If used in a building that is not very tight a some- 
what larger amount might be required. For fumigating 
large rooms it is better to place dishes containing the liquid 
in the upper part of the room as the fumes are heavier than 
air and settle. 
HYDROCYANIC ACID GAS. 
This is a very successful remedy against scale insects in 
California and is used in the following proportions : 
Cyanide of potassium, 60 per cent.,. . . . i ounce. 
Commercial sulphuric acid, .... i ounce, (fluid). 
Water 3 ounces. 
Space inclosed, 150 cubic feet. 
The fumes given off are extremely poisonous and care 
must be taken not to inhale them. The tree to be treated is 
first inclosed in a tent or box, the water and sulphuric acid 
poured , into a dish and set in, and then the cyanide added 
and the tent or box quickly closed and kept so for about 
one-half hour. 
