8 BULLETIN 1307, U. S. DEPARTMENT OE AGRICULTURE 
SUMMARY 
Dried fruits were fumigated with hydrocyanic acid gas. The 
fumigant remaining was determined on the day of fumigation and at 
intervals of 1, 7, 30, and 90 days thereafter. 
All fruits which were not in tight packages absorbed some hydro- 
cyanic acid. This was gradually dissipated, although a small 
quantity was left in many of the fruits at the end of 90 days. 
Dried fruits fumigated in commercial packages did not absorb as 
much hydrocyanic acid as those fumigated without such protection. 
No fumigant was absorbed by apricots tightly packed in a box lined 
with waxed paper, and the gas did not penetrate to the center of the 
box of tightly packed figs. This indicates that the process of fumiga- 
tion used would not be effective as a method of freeing dried fruits 
from insects if the fruits are tightly packed OT ^ wrapped in waxed 
paper. 
Candies absorbed a comparatively small q 
acid. The original absorption of nut meats was 
the fumigant was dissipated in a very short time. Cocoa absorbed 
a high proportion of the fumigant and retained it for some time. 
No hydrocyanic acid was absorbed through the rind of an American 
Swiss cheese. No fumigant penetrated to cheese tightly wrapped in 
tin foil, but the absorption was as high in cheese loosely wrapped in 
tin foil as in that which was not wrapped. 
Boiling with water in the absence of added acid for 30 minutes was 
not always sufficient to entirely remove the hydrocyanic acid. 
No conclusions as to the safety of fumigated foods for human con- 
sumption are drawn from the results reported in this bulletin. 
Chemical observations alone are reported here. Determinations 
of the quantities of hydrocyanic acid injurious to health lie in the 
domain of the pharmacologist. 
LITERATURE CITED 
(1) Anonymous. 
Ship fumigation. Preliminary report of the board appointed by the 
Surgeon General to investigate the subject of fumigation of ships. In 
U. S. Treasury Dept., Public Health Rpts. (1922), 37: 2744-7. 
(2) Bonjean, Ed. 
Emploi de l'acide cyanhydrique (prussique) pour la destruction des rats, 
des parasites et des insectes. In Rev. hyg. (1922), 44--' 776-794. 
(3) DeOng, E. R., and Roadhouse, C. L. 
Cheese pests and their control. Calif. Agr. Expt. Sta. Bui. 343 (1922), 
p. 419-424. 
(4) Heerdt, W. 
Zyklon-Verfahren. In Praktische Desinfektor (1921), 13: 9-11. 
(5) Jansen, J. D., Schut, W., and Wagenaar, M. 
Eenige Mededeelingen over de adsorptie van cyclon door vershillende 
levensmiddeien. In Chem. Weekblad. (1922)," 19: 373-375. 
(6) Ltjtrario. 
Experiences sur la diffusion de l'acide cyanhydrique dans les locaux 
fermes, et sur Faction de cet acide sur certaines marchandises (subs- 
tances alimentaires et tissus) et sur quelques animaux parasites. In 
Bull. off. intern, hyg. pub. (1921), 13: 367-376. 
(7) Simmons, P. 
Hydrocyanic acid retained by fumigated cheese. In J. Econ. Entomol. 
(1924), 17: 416-17. 
(8) Stock, P. G., and Monier- Williams, G. W. 
Preliminary report on the use of hydrogen cyanide for fumigation pur- 
poses. Great Britain Ministry of Health, Rpt. Pub. Health Med. 
Subjects 19 (1923), p. 19. 
o 
