5 
Secondl.v, the building to be fumigated must be fairly tight. If windows 
are very loose, paper should' he pasted over the cracks. Further, when possible, 
if the stories to be fumigated are not separated from each other, some tempo- 
rary inclosure should he made, thus insuring each story getting the maximum 
amount of gas. 
Find accurately the number of cubic feet in each story to be treated, mak- 
ing no allowance for machinery or empty bins. Allow .25 of a gram of cyanide 
for every cubic foot of space. After multiplying the number of cubic feet by 
.25 divide by 28.35 to reduce to ounces, and this result by 16, the final cp.iotient 
l)eing the number of pounds (avoirdupois) of cyanide needed. But experience 
has taught the writer that it is well to use two or three jars more on each floor 
than the above specifications call for to insure thorough work, hence it is wise to 
add nine or ten pounds more for each story, when making up your order. The 
amount of cyanide required having been determined, order it from a relialfle 
dealer, {iisisting upon p 8 per cent or 99 per cent grade of fused cyanide of 
potash. Avoid the use of a low grade. 
1 'he employment of cyanide of sodium in place of cyanide of potash has 
been discussed on page 3. The trade name “Cyanegg’’ is used to desig- 
nate egg-shaped masses of cyanide of sodium now on the market, each piece 
weighing one ounce. This is a convenient form in which to use this material. 
A half more sulphuric acid, liquid measure, than cyanide will be needed. 
For instance, if a building require 500 lbs. of cyanide, 750 lbs. of sulphuric acid 
are called for. This acid must he the best grade of eomniercial acid zvith a 
specific graz'ity of 1.83 or over. Anything belozu that should be rejected. 
Three pounds of cyanide (a convenient-sized charge) to a crock calls for 
4^2 Ihs. avoirdupois of acid, and 64 ^ lbs, avoirdupois (approximately 3^2 C[uarts) 
of water to each crock. The zvater should alzoays be poured in first, and the 
acid added. 
Get from a grocer a hundred or more manila sacks, No. 8 or No. 10 or 
No. 12. You will need two sacks for every three pounds of cyanide. Do not 
use the heavy paper sacks, so-called “sugar sacks.” Cloth sacks must never he 
employed. These bags are to be doubled, one being carefully placed inside 
another. The cyanide, after being broken up, is placed in these s-acks within an 
hour or two of the time when it is to he used ; hut must not lie left in the sacks 
for any length of time, four hours, or over night, for example. Torn sacks must 
be rejected. 
When ready to fumigate, hut not before, this cyanide is done up in 3 lb. 
packages,'^ using double manila bags, i. e., one inside another, of such size as to 
permit the paper to be l)rought together and securely tied above the cyanide with- 
out tearing. If cyanide of potash is left too long in paper sacks in a more or 
less humid atmosphere it absorbs moisture and the sacks are rendered insecure. 
As many 4-gal. crocks should be rented or purchased as there are packages of 
cyanide. If, however, the entire plant is not to be treated at one time, only 
sufficient jars are needed for the portion to be treated, since the same crocks can 
l)e cleaned and used again. These crocks after being thoroughly cleaned are in 
no way injured for household use later by being thus employed. 
*Two and one-half pounds if cyanide of sodium is used. 
