20 
8. Danger signs should be placed in position and a watchman sta- 
tioned outside until the operation is concluded. 
9. Before fumigating clean out the mills thoroughly and provide 
for the penetration of the gas to every portion by moving bags, 
boxes, ete. 
10. Do not fumigate in a high wind or in a low temperature. 
Between 65° and 85° I. should produce the best results. 
11. Begin operations in the upper floors and pass quickly down- 
ward, placing the cyanid gently in each jar. 
12. Fumigate preferably on a Saturday afternoon, lock the doors 
after operations are completed, and expose from twenty-four to 
thirty-six hours if possible. 
13. Never reverse the order of procedure. Always pour in the 
water first, next the acid, and lastly put in the cyanid in bags. 
14. The operator should never return to the building after the 
first fumes begin to issue. 
15. Everyone connected with the fumigation should constantly 
bear in mind the deadly nature of the cyanid and the gas and be con- 
versant with the process and the necessity of caution before the gas 
is evolved. 
ORDER OF PROCEDURE IN FUMIGATION. 
Briefly, the fumigation of a mill or granary includes the following 
steps: 
1. Measuring the mill and computing the amount of chemicals 
and number of generators required. 
2. Securing the chemicals and the generating jars. 
3. Preparation of the mill, including cleaning, sealing up as nearly 
air-tight as possible, and arrangement for ventilation from without 
after the conclusion of the fumigation, and preparing signs. 
4. Distribution of jars and measuring into each the proper amount 
of water. 
5. Breaking up the cyanid and weighing and placing it in 3-pound 
lots in sacks, temporarily storing it in tightly covered tin cans, 
preferably a can for each floor. 
6. Measuring out the acid and adding to water in jars. 
7. Placing a bag of cyanid in each jar, beginning with the top 
floor. 
8. Tightly closing and locking the building and seeing that all 
warning signs are in place, and, if necessary, stationing a watchman 
without to guard the building from entrance. 
9. Opening the building from without for ventilation. 
10. The collection and disposal, in the sewer or in a pit, of the 
residue, the cleaning of generators, and sweeping out dead insects 
and other débris before resuming work. 
[Cir. 112] 
