New York AGRICULTURAL EXPERIMENT STATION. 329 
The amount of cyanide to use-—The amount of cyanide to use 
depends upon the strength required and the size of the tent or 
box. For fumigating orchard trees in winter use 0.8 gram of 
cyanide per cubic foot of space inside the tent or box. For 
example, suppose a tree is to be fumigated with the box fumi- 
gator described in our Bulletin No. 181. This fumigator meas- 
ures 10x6x6 feet. It contains, therefore, 360 cubic feet. We 
wish to use the gas at a strength of 0.38 gram of cyanide per 
cubic foot. The amount of cyanide required would then be 
360x0.8—=108.0 grams? or 3.51 oz. 
After reducing to ounces use one and one-half times as many 
fluid ounces of sulphuric acid as cyanide, and one and one-half 
time as much water as acid. This would make the formula for 
fumigating a tree in a 10x6x6 ft. fumigator with gas containing 
0.38 gram of cyanide per cubic foot as follows: 
Cyanide of potassium 98-99% pure.......... 3.51 oz. avoir. 
RMT POOL ote oe ek ac Sarek caer eeeaeers Pre ik sie k 2k OZ 
eR a tare hia ore aos 8 ¥ Stull wn gthad,g.s.00%, 0.0 9 67e se" Clas “inl, 
The exact amount. of acid is not important. A small fraction 
of an ounce will make no difference. In this case 5 oz. would 
answer the purpcose or if preferred 54 oz. could be used. Like- 
wise eight ounces of water could be used in place of 7.9 ounces. 
The water should first be placed in the generating dish, which 
should be a flat-bottomed, open dish, preferably earthenware, the 
acid being added slowly. When all is ready, drop the cyanide 
into the dish. A very convenient way to handle the cyanide is 
to measure it out in small Manila paper bags and when ready 
_to set off the charge drop the bag with the cyanide into the acid. 
Cyanide of potassium can usually be had for about 38 cts. a 
pound and commercial sulphuric acid by the carboy (about 12 gal- 
lons) at 13 cts. a pound. At these prices the cost of the chem- 
icals to fill the above fumigator with gas containing 0.38 gram of 
cyanide per cubic foot would be about 7% cts. 
*One gram is equivalent to .08257 0z, avoirdupois, 
