2A4 FUMIGATION METHODS 
the most effectual method we have to clean up nursery 
stock of its insect pests, and has given great satisfaction 
where it has been judiciously handled. ‘There are 
cases in which the exposure to the gas was unneces- 
sarily long, resulting in marked injury to the trees. 
It is useless, of course, to subject trees to the gas which 
are free from insects. The gas treatment should find 
favor in warehouses, flour-mills, etc., where vermin 
are to be destroyed and no life is at stake, but I have 
met with no experience in such places. I cannot 
recommend it for conservatories or greenhouses where 
a mixed lot of plants are grown. In my own experi- 
ence I have found many kinds of plants suffer greatly 
in an exposure that is too weak and brief to kill all of 
the red spiders or mealy bugs. Ifa single house can 
be closed off and the stock is wholly of one kind of 
plants, as violets or chrysanthemums or carnations, it 
is possible to so adjust the treatment that no injury will 
befall the plants and the inse¢ts will be destroyed.— 
Prof. GEORGE C. Butz, Horticulturist Pennsylvania 
Agricultural Experiment Station. 
Rhode Island.—I believe that the gas treatment for 
the destruction of insects upon nursery stock is the 
only efficient method for the destruction of certain of 
the pests, and personally were I to buy plants fora 
large orchard, or for use in the orchards which I 
already have planted which are now free from San José 
scale, I would most surely buy them from some 
nursery which would fumigate trees before shipment. 
I believe that as the efficiency of this method of treat- 
ment is more fully understood and appreciated by 
warehouse and flour-mill owners that this will become 
