80 HYDROCYANIC- ACID GAS FUMIGATION IN CALIFORNIA. 
GENERAL CAUTIONS. 
Hydrocyanic-acid gas is one of the most deadly of gases, so that 
considerable care is necessary in its use. Such exaggerated cautions 
have been written, in view of its poisonous properties, that the public 
at large have come to believe that a single whiff of this gas will 
produce the immediate death of an individual. This erroneous idea 
should be corrected. A whiff of the gas will not cause immediate 
death; neither will two or three whiffs. If subjected to a strong gas 
for a minute or two, undoubtedly a person would be overcome. The 
writer has never yet had a record of a person killed by hydrocyanic- 
acid gas while fumigating. In California, men work around tents 
every night for weeks at a time without any ill effects. During these 
operations they are breathing the gas in a diluted form much of the 
time. Repeatedly field men are seen sitting, either to rest or eat 
their lunch, on the edge of a tent covering a tree which had been 
dosed a few minutes previously. The writer has personally stood 
within a foot of a generator for an hour at a time, taking tempera- 
tures of the escaping gas as different dosages were tried out, some 
of which would be in excess of a pound. Frequently the wind would 
waft the fumes into his face. Outside of an occasional dizziness and 
headache, no serious results were experienced. Scores of similar 
cases could be cited. 
These experiences have been mentioned, not with the idea of 
tempting people to be careless in the use of this gas, but merely to 
correct the erroneous conception that a whiff of the gas will cause 
instant death. This gas is most dangerous, and the writer has seen 
men who were subjected to a great strength of it for several minutes 
at a time overcome by its effects, although they revived later. If the 
proper precautions are taken the careful operator will run no risk 
whatever. Place the charge in the generating vessel with extended 
arm so that the head of the operator is away from the escaping gas. 
Being lighter than air, the gas rises straight up in a narrow column 
until several feet above the ground. As soon as the dosage has been 
set off, quickly leave the tent or room, whichever it may be. If this 
procedure is followed there is no danger of ill effects to the operator. 
