SOME RECENT OBSERVATIONS. 65 



Fig. 54.— Fumes of Hydrocyanic acid gas, arising from jar. (Author's illustration.) 



mills, warehouses, etc., and when handled with proper pre- 

 cautions by one conversant with its deadly nature, is not only 

 highly effective, but perfectly safe. We have used it repeat- 

 edly with success, and so far, with absolutely no accident, 

 but we are free to admit, that, realizing the inherent danger, 

 we take each step in the process with the utmost care. These 

 precautions have now, through repeated use, become auto- 

 matic, as it were, and we do not hesitate to handle this gas 

 as freely as we would the less dangerous and correspondingly 

 less effective bi-sulphide of carbon, and this department has 

 published from time to time circulars giving careful directions 

 for its use to millers who would fumigate their mills, and to 

 others. We will gladly mail these directions to any citizen 

 of Minnesota who desires them. 



As commonly employed .25 of a grain of cyanide is used 

 for every cubic foot of space to be fumigated, the amount 

 being reduced to ounces, and the charges tied up in three- 

 pound packages in double manila paper sacks. Each charge 

 calls for a four-gallon crock, similar to the one shown in photo- 



