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5 
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FUMIGATION OF ORNAMENTAL GREENHOUSE PLANTS. 3 
with straight sides are frequently sold with glazed earthenware tops. 
These tops or covers increase the cost of the generators and, further- 
more, are useless for fumigation purposes. Therefore, when genera- 
tors are ordered it should be indicated that tops are not desired. 
With this type of generator a cover may be improvised by using a 
piece of corrugated galvanized iron roofing or a board with cleats on 
the underside, to allow the free exit of gas. 
MISCELLANEOUS REQUIREMENTS. 
Correct scales or balances, reading in tenths of an ounce, are con- 
venient for accurate work. An 8-ounce graduate is desirable for 
measuring the acid and water. To avoid splashing of the acid it 
should not be poured from a carboy or bottle into the graduate but 
should be transferred to a porcelain pitcher, from which it may be 
poured with safety. It is well to have on hand a supply of small 
bags or tissue paper in which to place the cyanid. 
PREPARATION OF HOUSE FOR FUMIGATION. 
As a preliminary to fumigating the house it is essential that the 
exposed glass surface be examined carefully and all broken glass re- 
placed. All cracks should be thoroughly closed. The ventilators, 
Vi 
Fic. 2.—Methods of attaching rod and cord (a, b) to ventilator shaft of greenhouse so 
that the ventilators can be opened from the outside after fumigation. (Original.) 
both side and top, where possible, should be so arranged that they 
can be opened on the outside of the house upon the completion of the 
exposure. This can be accomplished by disconnecting the “ machine,” 
or gear, of the top ventilators and attaching to the central ventilator 
shaft (see fig. 2) an arm (a or 0) which can be controlled by a cord 
or wire which extends through the side of the house. The gears on 
the side ventilators may be disconnected so that the sash may be 
opened from the outside. If only one ventilator can be opened it is 
preferable that it be the one on the roof of the house. 
