The Proportions of Ingredients 
The Proportions of Ingredients 
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Experiments and experience have shown that the potassium 
cyanid should be ninety-eight per cent pure in order to give satis¬ 
factory results. The purchaser should insist on the cyanid being of 
at least that purity, and it should be procurable at not more than 
forty cents per pound. The crude form of sulfuric acid may be used. 
It is a thickish, brown liquid and should not cost more than four or 
five cents a pound. If a room is made tight, one ounce of cyanid for 
every one hundred cubic feet of space has been shown to be sufficient. 
It is combined with the acid and water in the following proportions: 
Potassium cyanid. 1 ounce 
Commercial sulfuric acid. 1 fluid ounce 
Water. 3 fluid ounces 
A Single Room as an Example 
Suppose a room to be 12 by 15 by 8 feet. It will contain 
12x15x8, or 1440 cubic feet. For convenience the writer always 
works on the basis of complete hundreds; in this case he would 
work on the basis of 1500 cubic feet, and thus be sure to have enough. 
The foregoing room, then, would require 15 ounces of cyanid, 15 
ounces of sulfuric acid, and 45 ounces of water. The room should 
be made as tight as possible by stopping all the larger openings, 
such as fireplaces and chimney flues, with old rags or blankets. 
Cracks about windows or in other places should be sealed with narrow' 
strips of newspaper well soaked in water. Strips of newspaper two 
or three inches wide that have been thoroughly soaked in water may 
be applied quickly and effectively over the cracks around the window 
sash and elsewhere. Such strips wall stick closely for several hours 
and may be easily removed at the conclusion of the work. 
While the room is being made tight, the ingredients should be 
measured according to the formula already given. The water should 
be measured and poured first into a stone jar for holding at least two 
gallons. The jar should be placed in the middle of the room, with 
an old rug or several newspapers under it in order to protect the floor. 
The required amount of sulfuric acid should then be poured 
rather slowly into the w r ater. This process must never he reversed; 
that is, the acid must never he poured into the jar first. The cyanid 
should be weighed and put into a paper bag beside the jar. All hats, 
coats, or other articles that wall be needed before the work is over 
