Fig'. 1. Convenient size for the Cyanide. 
Small mills, that is, mills in which there are not more than ten or 
twelve jars on a story, can be treated by dropping the charges by hand. 
We hnd that under ordinary conditions prevailing in mills, about 
twenty-hve seconds ela])se Itetween the dropping of the charge and the 
giving ofif of the fumes in fatal quantity. Where the door is not too 
much obstructed by spouts or machinery, tw^o level-headed men can 
walk rapidly from jar to jar, dropping a bag in each jar, and descend 
to the door below without delay, closing the trap door, or improvised 
cover of buildipg' ])aoer, as they go down. Ten jars could easily be 
treated thus in less than twenty seconds. In other words, the men 
would be in the story below before the jar drst treated began to give oft 
a dangerous (juantitv of gas, and as the gas always ascends, being 
lighter than air, operators on the door below are, for the time being, 
perfectly safe. use the ex])ression ‘Tor the time being” because we 
have in mind the fumigation of all stories of a dwelling above the 
cellar, yet two cats in the cellar were found dead after the process. 
Large mills, however, have to be strung. 
