108 VEGETABLE FORCING 
of the Toledo growers use a special wire cage in which 
the dry stems are placed and then soaked with water. 
Garbage cans (Fig. 34) are employed sometimes. 
The fires are always started in the lower part of the 
house, as on the walks, because the smudge rises slowly 
and gradually fills the house. The stems create a con- 
siderable degree of heat and, therefore, the fires should 
not be started close to wood or other inflammable ma- 
terial. One fire for each 50-foot unit of house 25 by 40 
feet wide will give satisfactory results. A little experi- 
ence will soon enable the operator to use the required 
amount of stems to make a good smudge. Some dry 
material, such as paper, small pieces of wood, corn cobs, 
etc, are placed in the bottom of the container, and the 
moist tobacco stems above. A common practice is to use 
a little kerosene to start the fires. 
Tobacco preparations in various proprietary forms may 
be purchased from nurserymen, seedsmen and other 
dealers. Most of them are excellent and some are con- 
sidered more efficacious than the burning of tobacco 
stems. They are also more convenient to use and the 
expense may be no greater, especially if the stems must 
be bought from a middleman instead of a factory, and 
shipped, perhaps, a long distance, thus incurring a heavy 
freight bill. 
Fumigating powders are in common use, These may 
be placed on shallow pans in the greenhouse walks, and 
a few drops of kerosene added to facilitate ignition. The 
powders burn slowly and gradually fill the house with 
fumes which are poisonous to all forms of aphids. 
Liquid extracts of tobacco are popular among florists, 
and they are used to some extent by vegetable growers. 
These concentrated forms may be vaporized by pouring 
them on hot pipes, plunging hot irons into kettles of the 
extracts, or by the use of hot steam admitted through a 
steam hose into the extract. Special vaporizing lamps 
