INDUSTRIAL FUMIGATION AGAINST INSECTS 



27 



released into the room from the outside. The cylinders are all equipped 

 with fittings that can be connected with the piping system (fig. 23). 



The minimum quantity of this mixture that should be drawn from 

 a cylinder at one time is 10 pounds, since it is difficult to withdraw 

 uniform mixtures of carbon dioxide and other fumigants in smaller 

 quantities. When portions of cylinders of mixed gases are used, it 

 it well to follow the instructions of the manufacturers. 



Where the floors are painted or varnished, the cylinders should be 

 placed in shallow pans or on several thicknesses of newspaper, to 



Figure 23. — Battery of 10 cylinders of ethylene oxide-carbon dioxide mixture 

 attached to manifold, heaters, and distributing pipes connecting with storage 

 vaults (not shown) in room. In lower background is a 6- by 8- by 10-foot 

 metal fumigation vault, which opens into the room beyond. 



prevent damage in case the liquid should run down the side of the 

 cylinder. 



This mixture is very effective in rooms that are nearly airtight, 

 but it should not be used in rooms that are loosely constructed. After 

 the fumigation and ventilation all that is necessary is to roll the empty 

 cylinders out of the room and return them to the owner. 



Fumigation With Methyl Bromide 



Methyl bromide, one of the newer fumigants, is proving to be exceed- 

 ingly useful in certain types of fumigation work. It is a colorless 

 liquid which boils at 40.1° F. At room temperatures it is a gas weigh- 

 ing 0.247 pound per cubic foot. It is obtainable commercially in 

 liquid form in 1-pound cans or in cylinders containing 10, 50, or 150 



