170 INSECTS IXJURIOrS TO STAPLE CROPS. 



hours, its germinating power will be unimpaired. In open 

 cribs and badly infested buildings it may sometimes be 

 necessary to use a double quantity of the reagent and 

 repeat treatment at intervals of about six weeks during 

 the warmest weather.^' 



When possible it is always desirable to fan the grain 

 immediately after fumination, thus removing the dead 

 insects, and to thoroughly clean the granary before refill- 

 ing it. 



"Mills and other buildings, when fonnd to be infested 

 throughout, may be thoroughly fumigated and rid of 

 insects by a liberal use of the same chemical. A good time 

 for this work is during daylight on a Saturday afternoon 

 or early Sunday morning, closing the doors and windows 

 as tightly as possible and observing the precaution of 

 stationing a watchman without to prevent any one from 

 entering. It is best to begin in the lower story and work 

 upward to escape the settling gas. The building should 

 then be thoroughly aired, and the grain stirred early 

 Monday morning. 



" For the fumigation of a building or a reasonably close 

 room it is customary to evaporate a pound of bisulfide for 

 every thousand feet of cubic space. In comparatively 

 empty rooms, and in such as do not admit of being tightly 

 closed, two or three times the above quantity of the chem- 

 ical is sometimes necessary. 



Cauiio)]. — " Certain precautions should always be 

 observed. The vapor of bisulfide is deadly to all forms of 

 animal life if inhaled in sufiicient quantity, but there is no 

 danger in inhaling a small amount. The vapor is highly 

 inflammable, but with proper care that no fire of any kind, 

 as, for example, a lighted cigar, lantern, or light of any 



