26 



CIRCULAR 369, U. S. DEPT. OF AGRICULTURE 



(fig. 25). A cylinder of the mixture will empty itself in about 5 

 minutes after the valve has been opened wide. 



When the valves are opened wide, the force of the escaping gas 

 often causes the cylinders to topple over. To avoid this, the cylin- 

 ders can be lashed to the walls of any stationary object, or several 

 cylinders can be lashed together with the discharge vents pointing 

 in opposite directions. 



Unless a large number of cylinders are used in a fumigation, the 

 valves can be opened without the use of a gas mask, although it is 

 not advisable to stay in a strong concentration of the gas for any 

 appreciable length of time. Before starting the fumigation it is 

 well to see if the valves on all the cylinders can be opened easily by 

 hand; any that are stuck should be loosened with a wrench. 



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321 



Figure 21 



: of ethylene oxide-carbon dioxide mixture being emptied automati- 

 cally by the pressure of carbon dioxide within. 



If desirable, a storage room can be piped in the same manner as 

 for liquid hydrocyanic acid, and the ethylene oxide-carbon dioxide 

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

 equipped with fittings that can be connected with the piping system 

 (fig. 26). 



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 

 is 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 

 prevent damage in case the liquid should run down the sides 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. 



