HOW THE GAS IS MADE II 



and crystalizes when cold. It is easily soluble in 

 water. Immediately after the room, tent, or other 

 inclosure has been ventilated the desired length of time 

 the contents of the jar should be emptied on a manure 

 pile, in a hole prepared especially for that purpose, or 

 under the tree close to the trunk. As the acid and 

 potash left behind are both excellent fertilizers they 

 should be saved by composting them either with 

 manure or dirt. The residue consists of sulphate of 

 potash, sulphuric acid, and water. The sulphuric acid 

 will unite with lime in the soil, forming gypsum. 

 Never pour the residue in an exposed place, where a 

 person would be liable to step in it, or where a tent 

 can be dragged through it. 



No dangerous deposit formed. The question is 

 often asked about the possibility of hydrocyanic acid 

 gas forming a deposit upon any of the substances with 

 which it might be brought in contact in its ordinary 

 use as a fumigant, either in greenhouses or in buildings 

 infested by indoor insects. Dr. H. W. Wiley, chemist 

 of the United States Department of Agriculture, 

 states that there is no possibility whatever of such a 

 contingency, unless the gas comes in contact with some 

 alkaline body, such as soda or potash, with which it 

 would form a salt. The soluble cyanides are extremely 

 poisonous, and if this gas were to act upon lye, or any 

 similar alkaline body, a certain amount of cyanide 

 would be produced. In a dry room, in the absence of 

 alkaline bodies, there could not be any possible danger of a 

 poisonous body being formed. 



