18 



CIRCULAR 3 6 9, U. S. DEPARTMENT OF AGRICULTURE 



Figure 18. — Fumigating a tobacco warehouse with hydrocyanic acid gas. using the 

 liquid method. The liquid hydrocyanic acid in the cylinder on the scales is being 

 forced, by air pressure generated by -a small electrically driven compressor, through the 

 rubber tubing from the cylinder tb the piping system installed inside but protruding 

 through the walls. 



Figure 19. — Equipment for fumigation of flour mill from loading platform. Note G 

 cylinders of liquid hydrocyanic acid, 2 electric motors, outlets in the wall leading to 

 6 piping systems to carry fumigant to 6 separate compartments, floors, or pipe lines 

 within. The 2 motors are forcing, by air pressure, the liquid hydrocyanic acid in 2 

 of the cylinders through rubber hose 'into 2 of the systems of copper piping within. 

 Note placard on door warning of danger. 





