36 
FUMIGATION INVESTIGATIONS IN CALIFORNIA. 
Table II. — Experiment to determine the effect of different proportions of water on the 
U mperature of the resulting gas. 
Amount of chemicals used. 
Tempera- 
ture of the 
acid and 
waU't mix- 
ture. 
Highest 
tempera- 
ture of the 
hydro- 
cyanic-acid 
gas. 
Tempera- 
ture of the 
gas one 
minute 
from start 
of genera- 
tion. 
Cyanid. 
Acid. Water. 
Ounces. 
5 
5 
5 
5 
5 
5 
5 
Ounces. Ounces. 
5 
5 10 
5 15 
20 
25 
30 
5 40 
°F. 
180 
190 
170 
100 
145 
136 
125 
°F. 
124 
126 
128 
128 
118 
108 
90 
°F. 
115 
121 
109 
105 
105 
104 
-7 
In this experiment 5 ounces (avoirdupois) of cyanid and 5 ounces 
(fluid) of acid were used for each test. The proportions of water were 
varied, 5, 10, 15, 20, 25, 30, and 40 ounces, respectively, being used. 
As a result the proportion of water to 1 part of acid or 1 part of cyanid 
was 1, 2, 3, 4, 5, 6, and 8, respectively, for the different tests. These 
generations were made in a H-gallon fumigating vessel in a room. 
The temperature of the escaping gas was taken at the mouth of the 
pot. The temperature of the acid-water mixture was taken one 
minute after pouring the two together. The cyanid was then added. 
The maximum temperature of the escaping gas is always realized 
within the first minute, usually thirty to forty seconds after the gener- 
ation commences. Examination of the maximum temperature of the 
gas as noted in the third column of the table above indicates that the 
temperature of the gas is reduced when large proportions of water 
are used. When using from 1 to 4 parts of water, the temperature 
is nearly uniform, but with 5 parts of water the decrease becomes 
marked. Repetitions of the above experiment gave similar results. 
The violence of the reaction and the temperature of the gas are affected 
more or less by the size of the pieces of cyanid. A very violent reac- 
tion results from the use of cyanid in powdered form. 
We would expect that to increase the proportion of water woidd 
decrease the temperature of the gas. One reason is shown in tin- 
table under the column marked " Temperature of the acid and water 
mixture." As the proportion of water to sulphuric acid becomes 
larger the resulting temperature of the mixture is lessened. Hence 
^vvhen the cyanid is added to the mixture as high a degree of heat to 
start the reaction is not developed as when the smaller proportion of 
water is used, and in consequence gas is evolved less violently. 
THE TEMPERATURE OF THE GAS WHERE LARCH AND SMALL DOSAGES ARE USED. 
In an experiment to determine the temperature of the gas result- 
ing from large and small dosages (Table III) the chemicals were used 
in the following proportion-: Cyanid 1 part, acid 1 part, and water 
