8 FUMIGATION METHODS 
and the box system, designated by me as the ‘‘ Emory 
Fumigator,’’ has been perfected, and is now commonly 
used by orchardists and others. 
Since 1894 the gas has also been used in green- 
houses for the destruction of certain pests. The 
demand for fumigated trees led me to conduct an 
extensive series of experiments with the gas upon 
nursery stock of various kinds and grades. ‘These 
tests, begun the fall of 1896 and completed the spring 
of 1899, have shown conclusively the maximum and 
minimum amount of gas young trees will withstand 
without injury. Many obscure points about the con- 
struction and management of fumigating houses have 
been made clear. ; 
In 1898 I first suggested the use of hydrocyanic 
acid gas as a remedy for the destruction of insects in 
mills, elevators, and warehouses. ‘The system has 
since been perfected under my dire¢tion, and it is now 
in general use in this and other countries. In 1900 I 
demonstrated that the gas could be used in tight 
buildings with perfect success and safety, even in the 
thickly populated distri¢ts of a city, when properly 
handled, for the destruction of certain pests, including 
rats and mice. The fumigation of street-cars and 
railroad coaches to destroy bedbugs and other vermin 
is commonly practiced in many places. The gas is 
also employed to rid houses of undesirable pests, but 
in such cases should be handled with great care. 
