﻿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 were withdrawn for analysis.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. 



Sodium 

 cyanide. 



Number 

 of times 

 chamber 

 was evac- 

 uated. 



Hydrocyanic acid after— 



Oday. 



1 day. 



4 days. 



7 days. 



14 days. 



30 days. 



60 days. 



90 days. 



Oz. per 

 100 cu. ft. 



1 



1 



1 



1 



2 



2 



2 



2 



4 



4 



4 



4 



6 



6 



6 



6 





 1 

 2 



3 





 1 



2 

 3 





 1 

 2 

 3 





 1 



2 

 3 





3.3 

 8.3 



8.3 



3.3 

 3.3 

 4.2 

 3.3 



2.5 

 6.6 

 3.3 

 3.3 



5.0 

 5.0 

 5.0 

 4.2 



5.0 

 10 

 13 

 12 



1.7 

 2.5 

 2.5 

 1.7 



1.7 

 2.5 

 2.5 

 3.3 



4.2 

 3.3 

 4.2 

 3.3 



4.2 

 6.6 

 8.3 

 10 



O.S 

 .8 

 .8 

 .8 



1.2 

 1.7 

 1.7 



2.5 



3.3 

 2.5 

 3.3 

 2.5 



3.3 

 5.0 

 6.6 

 6.6 



None. 



None. 



0.8 



.8 



1.2 

 1.2 

 1.2 

 .4 



3.3 

 2.1 



2.5 

 1.7 



2.5 

 3.3 

 3.3 

 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 



1 





20 

 16 

 16 

 12 



58 

 42 

 25 



42 



25 



42 

 42 

 58 



4.2 

 8.3 

 6.6 

 3.3 



13 



17 

 17 

 20 



6.6 

 27 

 30 

 20 



