98 GENERAL ADVICE 



the liquid, and which is very destructive to insect 

 life while it does not injure the plants. Fumi- 

 gation may be practiced even in hotbeds and cold- 

 frames, as shown in Fig. 97, which illustrates a 



97. Fumigating a hotbed. 



fumigater with the outlet pipe running into the 

 frame and with draft supplied by means of a 

 hand bellows. 



The most efficient means of destroying insects 

 and fungi, however, is by the use of various 

 sprays. The two general types of insecticides 

 have already been mentioned those which kill by 

 poisoning, and those which kill by destroying the 

 body of the insect. Of the former, there are 

 three materials in common use Paris green, 

 London purple and hellebore.* Of the latter, 



*PARIS GREEN. Paris green, 1 pound; water, 200-300 gallons. If this 

 mixture is to be used upon peach trees, 1 pound of quicklime should be 

 added. Repeated applications will injure most foliage, unless lime is 

 added. Paris green and Bordeaux mixture can be applied together with 

 perfect safety. Use at the rate of 4 ounces of the arsenites to 50 gallons 

 of the mixture. The action of neither is weakened, and the Paris green 

 loses all caustic properties. For insects which chew. 



LONDON PURPLE. This is used in the same proportion as Paris green, 

 but as it is more caustic it should be applied with two or three times its 

 weight of lime, or with the Bordeaux mixture. The composition of Lon- 



