ABSORPTION OF HYDROCYANIC ACID. 
11 
which the air was permitted to enter until normal atmospheric 
pressure had been attained. After the products had been exposed 
to the fumigant in this manner for an additional 50 minutes outside 
air was drawn over them for 10 minutes to remove the hydrocyanic 
acid. They were then taken from the chamber for analysis. 
The treatment of the second series was conducted in the same 
manner as that of the first, except that at the completion of the 
50-minute exposure the chamber was again evacuated until the 
gauge read 25 inches, air was introduced until atmospheric pressure 
was reached and, after a further 2-minute aeration, the products 
were withdrawn for analysis. 
The treatment of the third and fourth series was the same as that 
of the second, except that the evacuation at the end was repeated 
once and twice, respectively, with intermediate aerations of 2 minutes 
in each case. 
Determinations of hydrocyanic acid were made, after distillation 
with tartaric acid, by the method of Viehoever and Johns (23), on 
the day of fumigation (except in the first series) and at intervals 
thereafter. A delay with the first series made it impossible to con- 
duct the analyses on the same day. The products were stored in"a 
large, well-ventilated room during the intervals, at a temperature of 
about 70° F. The results of the examinations are recorded in 
Tables 4, 5, 6, 7, and 8. 
Table 4. — Hydrocyanic acid (parts per million) in fumigated navy beans. 
Number 
Sodium J tim . es 
cyanide. Camber 
was evac- 
uated 
Hydrocyanic acid after- 
day. ■ 1 day. 4 days 
days. 
7 days. 
3.3 
1.7 
3.3 
2.5 
4.2 
2.5 
3.3 
1.7 
2.5 
1.7 
6.6 
2.5 
3.3 
2.5 
3.3 
3.3 
5.0 
4.2 
5.0 
3.3 
5.0 
4.2 
4.2 
3.3 
5.0 
4.2 
10 
6.6 
13 
8.3 
12 
10 
14 days. 
30 days. 
days. 
90 days. 
Oz. per 
lOOcu.ft. 
1 
1 , 
1 
1 
3.3 
8.3 
8.3 
4.2 
8.3 
0.8 
.8 
.8 
1.2 
1.7 
1.7 
2. 
None. 
None. 
0.8 
.8 
1.2 
1.2 
1.2 
4 
3.3 
3.3 
2.5 
2.1 
3.3 
2.5 
2.5 
1.7 
3.3 
2.5 
5.0 
3.3 
6.6 
3.3 
6.6 
3.3 
0.4 
.6 
1.2 
1.2 
1.2 
.4 
2.1 
2.1 
2.1 
1.7 
2.1 
2.9 
2.5 
2.5 
0.4 
Trace. 
1.2 
.4 
.4 
.4 
1.2 
1.7 
1.7 
1.7 
1.7 
2.5 
1.7 
1.7 
