6 
to the outside of the house. The cyanide can then be lowered into 
a jar while the person is on the outside of the house. If heavy bags 
are used for the cyanide, the jars can be placed in order and 
bag placed beside the jar. When all is ready, move rapidly along 
the row of jars placing the bags in the acid and leave the house at 
once. 
Wdien a large greenhouse is to be fumigated, it would be well 
to haye several jars, so that the gas will be thoroughly distributed 
throughout the greenhouse. V entilators should be arranged in 
such a way that they can be opened from the outside to air the 
house. One should be careful to remove their cats or any other 
pets from the house before the fumigation is started. If 
the cat is forgotten, one should not go into the house to get it after 
the cyanide is started; in fact, under no circumstances should the 
house be entered after the fumigation is started until such time as 
the house has been thoroughly ventilated. The dose which is in 
general use is from one ounce to live ounces of potassium cyanide 
per thousand cubic feet. It would we well to first try the lighter 
dose and if the insects are not killed and the plants are. uninjured, a 
stronger dose should be used. 
Fumigation is of value for a number of insects, for example: 
White Fly, Violet Aphis or Green Fly of violets, Green Fly, Mealy 
Bugs, Scale Insects, Thrips, etc. Some are more easily killed than 
others and in most cases a strong dose for a short period will be 
more beneficial and less apt to injure the plants than a milder dose 
continued for a longer period. One florist, who also raises truck 
crops in the greenhouse, says that he regularly and successfully 
fumigates with one ounce to the thousand cubic feet, over night, 
without injuring the plants. Three ounces of cyanide to a thou- 
sand cubic feet has been used successfully on ferns, while the 
double English violets will stand a dose of six ounces to a thou- 
sand cubic feet without injury. Single violets as the California 
and the Princess of Wales have been slightly injured by six ounces 
so that it will be advisable to use about four ounces in that case. 
The temperature of the house has to be 60° or a little bit above and 
the time of the dose about a half an hour. Five ounces to a thou- 
sand cubic feet have been used over night for cucumbers without 
injuring the plants in the least, while the author knows of a case 
where no account was taken of temperature or humidity, the tem- 
perature having been about 75° and the humidity probably great. 
