MILLS AND OTHER BUILDINGS l6l 



poured upon it. The cyanide is afterwards dropped 

 into the liquid, bag and all. The acid soon eats 

 through the paper and a bubbling reaction follows, 

 similar to that produced by placing a piece of red-hot 

 iron in cold water. This lasts a few moments only, 

 or until the acid acts upon the cyanide. 



A cloud of white steam is almost instantaneously 

 disseminated throughout the room or enclosure. The 

 odor of this gas is decidedly that of peach pits, and is 

 therefore easily detected. It is considered one of the 

 most deadly poisons known to chemical science and is cer- 

 tain death to any animal inhaling it. If a person 

 should breathe his lungs full of it he would not live 

 to know when he took his second breath, if he got it 

 at all. Attention has been called to the dangerous 

 character of the cyanide and this gas in each chapter, 

 and the writer again cautions those who are interested 

 in the subject to handle the material with great care. 

 When so handled there is no danger whatever, and 

 the results are satisfactory in every respect. The 

 effects on animal life given in Chapter IV. should be 

 carefully read in this connection. 



Resisting power of insecJs. After much experi- 

 mental work and many practical tests, we have found 

 that the most resistant insects infesting grain and 

 manufactured products are destroyed when the gas is 

 generated at the rate of 0.25 gramme cyanide per 

 cubic foot of space enclosed. The adults of the Med- 

 iterranean flour moth, Ephestia kuehniclla, the Angou- 

 mois grain moth, Sitotroga cerealella, and the Indian 

 meal moth, Plodia interpunctella , are destroyed readily 

 with 0.12 to 0.15 gramme cyanide per cubic foot. The 



