16 
Frequently these precautions are not observed, and although no 
casualties are on record it is the part of wisdom always to be on the 
safe side. 
PROCESS OF FUMIGATION. 
In the process of generating the gas the water is usually measured 
in a glass beaker indicating ounces, and poured into an earthenware 
crock or generator. To this is added the acid, measured in the same 
beaker, which is slowly and gently poured into the water to avoid 
splashing or boiling. The acid should never be placed in the genera- 
tors first, as advised by some writers, since experience shows that 
this is dangerous, spattering being almost certain to follow. When 
the acid is poured into the water in the jar an ebullition of vapor 
sometimes arises. 
When the cyanid of potash is finally dropped into the combined 
acid and water mixture an ebullition or bubbling also takes place 
similar to that which is produced by a red-hot iron dipped into cold 
water. Next is given off the hydrocyanic-acid gas, the most poi- 
sonous gasincommon use. It is colorless and has an odor which is 
likened to that of peach kernels.? If the fumes are inhaled they are 
almost certain to prove fatal; hence the necessity of extreme care 
and the advisability of two intelligent operators in this work. It is 
even advisable, especially when the first fumigation is undertaken, 
that one who has had experience with this method of fumigation be 
present to give directions. The odor is decidedly metallic, hike that 
produced by striking two pieces of metal together, or of metal against 
stone. 
In preparing cyanid of potash for use it should be broken into 
lumps about the size of an egg or a little smaller, by pounding it on 
a stone in the open. The cyanid should never be broken in the 
hands nor should it be handled without rubber or leather gloves. 
The smaller fragments, if not too many, are serviceable when equally 
apportioned as regards large and small particles, and wefghed out 
in 3-pound lots and placed in paper bags or sacks. 
The bags should be of moderately thin paper, because if as thin as 
tissue the action of the acid might be so rapid as to constitute an ele- 
ment of danger. If too thick, action would be delayed or checked, 
which would militate against the desired results. Before use, the bags 
should be placed in a can and kept free from moisture, which the 
eyanid salt is apt to absorb from the air, affording opportunity 
for leakage through the bag. In some cases, to avoid this leakage, 
two thin bags, one within the other, might be necessary. Washburn 
experimented in the use of two sacks with the result that at least 
20 seconds elapsed before the gas was evolved. 
«The writer fails to detect the resemblance. 
[eins 
