56 BULLETIN 737, U. S. DEPARTMENT OF AGRICULTURE. 
coming in contact with the skin. When the chemicals are handled 
with care and all details of the method understood, however, there is 
no special danger and the method has been used in insect control for 
many years with few records of serious accidents. 
EFFECT OF HYDROCYANIC-ACID GAS ON THE QUALITY OF TOBACCO. 
-Hydrocyanic-acid gas is slightly lighter than air and all traces 
of the gas are quickly removed from the tobacco by thorough airing. 
In order to determine whether or not any deposition of cyanogen 
in the cigars occurs as a result of the cyanid treatment different lots 
of freshly made cigars were fumigated at Key West, Fla., in 1912, 
and sent to the Bureau of Chemistry, United States Department of 
Agriculture, for examination. A list of the different lots of cigars 
sent is shown in Table VIII. 
TABLE VIII.—Effect of hydrocyanic-acid gas on quality of cigars. Fumigation 
tests at Key West, Ila. 
Cyanid of pot- 
Date fumigated. Benes oe Exposure. 
space. 
1912. Ounces. Hours. 
AUIS ZO) Serenct Se) Soe Ra meet aS eee ah ey Ea ERR eee Ca ee ees ae 8 24 
SEN Ae Ra Se Gee aaa emer da eo Uo ie aoa oe 8 24 
IN Teat aah te et See. SNR tek che OE SRE a oy Sn eee Rea 4 48 
May AZO ee Oe eae ere See AE ag I sh BU laa ya 4 24 
[RUBE Vee Seo Oe vaMr ars ae Aa pam Rhy a tek Mle Peer ne ms ey iety ee Ae manera 8 36 
dru Ve H Ee a ee Pere rs ee eee Le Sa aie RT 8 24 
immeyle eho itis ies duet ty LG to el eds a atlas ae eh ale at 8 24 
Not fumigated. (Used as check on treated lots.) 
All lots of cigars were exposed to the air for a short time after 
fumigation, and then sealed. As the amount of potassium cyanid 
used was greater than is ordinarily employed in fumigation, the test 
was a severe one. The cigars were received by the Bureau of Chem- 
istry on July 8. The following report was received on November 12, 
1912, from Mr. R. E. Doolittle, acting chief of the Bureau of Chem- 
istry: “ We have made a careful examination of the eight samples 
of cigars submitted by you on July 8 last, and we are unable to detect 
the slightest trace of hydrocyanic acid in any of the samples.” 
Samples of cigars fumigated by the cyanid process and untreated 
cigars of the same brand were submitted to a number of expert 
cigar men at Key West, Fla., in order to ascertain if fumigation in 
any way affected the flavor or quality of the cigars. All reported 
that no difference between the treated and untreated cigars was ap- 
parent, the uniformity of burn, capacity for retaining a light, and 
color of ash appearing normal. 
