4 
the doors and windows are left unlocked or unfastened, so that they 
may be opened from without. The fireplace flues in the different rooms 
should be stuffed with paper and the registers closed. Carpets and 
rugs, where possible, should be cleared away from the floor to prevent 
their being burned should the acid spatter or boil over. As generators, 
porcelain basins or preferably jars of a capacity of at least 2 gallons 
should be placed in each room; and if the rooms are large ones, two or 
more such vessels should be provided. One vessel will suffice for each 
2,000 or 3,000 cubic feet, preferably the former amount. Under each 
of these vessels a rather thick carpeting of old newspapers should be 
placed, or a larger vessel, and care must be exercised to see that none 
of the vessels are cracked, on account of the danger of breakage from 
the heat generated by the process. Deep vessels are more satisfactory 
for the experiment than the wash basins often used, but the latter are 
always available and will serve the purpose. Deeper vessels give greater 
depth to the water and acid and accelerate the chemical action, and 
there is less danger of spattering. Whenever the room is of such size 
that much more than 2 pounds of cyanide must be employed for it, it 
is perhaps better to make two charges of half size for such room. 
The cyanide should be broken up into lumps not exceeding twice the 
size of a walnut, the powdered and smaller fragments serving equally 
well, and put in paper bags in pound or one-half-pound lots. The bags 
should be of very thin paper. If they are of thick, heavy paper, the 
action of the acid is delayed and sometimes prevented completely. If 
there is any danger of this, make two or three slits in the bottom of each 
bag to facilitate the entrance of the acid. 
After the house has been put in a state of readiness for the experi- 
ment, and the vessels for the charges have all been placed in their 
proper locations, the requisite amount of water indicated by the table 
already prepared should be poured into each of the different vessels. 
Following this the proportionate amount of acid (half that of the water) 
should be added slowly to the vessels now containing the water; never 
in the reverse order. Considerable heat will be developed by the addi- 
tion of the acid, and some acid fumes may come off, but these are 
harmless. The cyanide, previously weighed out, should be distributed 
through all the different rooms in the proper amounts, placing the bags 
alongside of, not in, the generating vessels. 
The house is now in readiness to be fumigated. Coats and hats and 
everything needed outside must be removed, and preferably two per- 
sons should then go to the top of the house, taking different rooms on the 
same floor to expedite the process, and place the bags containing the 
cyanide gently into the vessels to receive them. The chemical action 
will begin at once, but the gas will not rise to any extent for a few 
seconds or a quarter of a minute, and there is ample time to leave the 
room quickly without any danger of breathing any of the gas. Having 
