MILLS AND OTHER BUILDINGS 163 
is now easy to determine the amount of acid and water, 
as a half more acid, liquid measure, than cyanide, and 
a half more water than acid are used; thus: 53 + 2 
= 26.5, which, added to 53, equals 79.5 ounces of acid, 
or practically 5 pounds, liquid measure. Again, 79.5, 
or practically 80, as we usually discard fractions, 
divided by 2 equals 40, which added to 80 makes 120 
ounces of water. 
Therefore, a room 20x 30x Io feet requires 53 
ounces, by weight, of cyanide, 80 ounces, liquid 
measure, sulphuric acid, and 120 ounces, liquid meas- 
ure, water. ‘The total cost of chemicals will be about 
$1.25. 
A pplication.—The methods used for generating the 
gas in large enclosures, such as a mill or other building, 
is not unlike that illustrated in Fig. 70, Chapter XIV. 
In our early experimental work it was thought desir- 
able to weigh the cyanide in bags of one pound each, 
but more recent practical tests have shown that 
it is more economical and satisfactory to have it 
weighed out in packages of three poundseach. Where 
used in this manner the jars or wooden vessels for 
acid and water should hold two or three gallons 
each. 
If, for example, we had a room in which 18 
pounds of cyanide were required, it would be weighed 
out in six packages of three pounds each. Each 
package will require a separate generator; therefore, 
six crocks or wooden vessels will be necessary. They 
should be arranged at various places in the room. 
Strings should be arranged so as to hang directly 
over each vessel, and carried through screw-eyes in 
