84 FUMIGANTS 
The usual method is to burn stems or dust, or to vaporize liquid 
extracts of tobacco, or to make use of a specially prepared punk now 
on sale in stores. The last is usually the most satisfactory method. 
It is desirable in tobacco fumigation to generate the smudge near 
the level of the floor, because it rises rather rapidly, and if generated 
at the height of the benches, much of the strength of the fumigant will 
be concentrated near the roof. 
