28O FUMIGATION METHODS 



the bugs to their c^estrudlion till Monday morning, 

 Then open doors and windows, and thoroughly venti- 

 late before going to work." 



The vapor of carbon bisulphid takes fire in air at 

 about 300 F. and burns with a faint blue flame, diffi- 

 cultly visible in daylight, but evolving considerable 

 heat and decomposing the carbon bisulphid into carbon 

 dioxide (CO,) and sulphur dioxide (SO 2 ). The latter 

 is the familiar gas given off by the burning of sulphur 

 matches and is a strongly poisonous, suffocating gas 

 which should not be inhaled. Carbon bisulphid vapor 

 mixed with three times its volume of oxygen, or an 

 amount of air containing that amount of oxygen, forms 

 a mixture which is very highly explosive upon ignition. 

 As 21 per cent, of the air is oxygen, one volume of 

 liquid carbon bisulphid evaporated in 5,357 volumes of 

 air would form such a mixture. An atmosphere com- 

 posed of one volume of carbon bisulphid vapor to 

 approximately 14.3 volumes of air is liable to violent 

 explosion in the presence of fire of any kind whatever, 

 or a temperature of about 300 F. without flame. We 

 have here about the maximum danger-point from 

 explosion in the use of carbon bisulphid. 



Exterminating the flour moth. My experience with 

 the Mediterranean flour moth is of nearly seven years' 

 standing. Until I took charge of my mill six years 

 ago I had never seen nor heard of the insect, and when 

 I found it here and learned what it was I doubted 

 whether such a delicate little creature could do any 

 more harm than a house-fly. I soon had evidence, 

 however, of its capacity for mischief. For one day it 



