FUMIGATION OF ORNAMENTAL GREENHOUSE PLANTS. fi 
MIXING THE CHEMICALS. 
After the generators have been distributed throughout the green- 
house, and before the chemicals have been mixed, the cyanid should 
be weighed accurately and the proper amount for each generator 
placed in a paper bag near the generator. The chemicals should be 
mixed invariably in the following manner: First, measure and place 
in each generator the amount of water required; second, measure and 
place in each generator the amount of sulphuric acid required; third, 
drop the cyanid into the diluted warm acid in each generator, close 
the covers, immediately leave the house, and post a danger sign on the 
closed door. The cyanid should be dropped gently, not thrown, into 
the generators, and the operator should begin at the generator 
farthest from the door and work toward the door. In case there are 
two rows of generators the cyanid should be dropped simultaneously 
by two operators. As little time as possible should elapse between 
the addition of the acid and the addition of the cyanid, as the heat 
which is liberated by the mixing of the acid and water assists in the 
generation of the gas. 
The residue left in the Eeneratone after fumigation should be 
buried or poured into a sink and the generator washed before being 
stored for future operations. | 
NUMBER OF GENERATORS TO BE EMPLOYED. 
The number of generators will depend largely upon the size of the 
house, and they should be so arranged that the gas will be uniformly 
distributed throughout the inclosure. To secure this advantage, it is 
advisable that a number of generators be used rather than one large 
generator. Generators should be spaced from 20 to 25 feet apart, 
and in case of a ight wind a few extra generators should be placed 
on the windward side of the house. An ounce to each jar is as small 
a dose as is practicable, unless the eperie iain are well rounded inside 
at the base or well tilted. 
EXPOSURES. 
Short exposures with a greater strength of gas have been found 
more satisfactory than a weaker strength of gas overnight. In fact, 
better results will be gained if the exposures do not exceed one to two 
hours. An exposure of one hour is satisfactory in most instances. 
Short exposures also have the additional advantage of permitting 
the house to become thoroughly aerated previous to the rising of 
the sun. 
