18 



CIRCULAR 369, U. S. DEPT. OF AGRICULTURE 



Figure IS. — 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 to the piping system installed inside but protruding 

 through the walls. 



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

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

 six piping systems to carry fumigant to six separate compartments, floors, or pipe 

 lines within.* The two motors are forcing, by air pressure, the liquid hydrocyanic acid 

 in two of the cylinders through rubber hose into two of the systems of copper piping 

 within. Note placard on door warning of danger. 



