London Purple. — This is a by-product in the manufact- 

 ure of aniline dyes, produced by Hemingway's London 

 Purple Company, of London, England. It contains nearly 

 the same percentage of arsenic as Paris green and is much 

 cheaper. It is principally an arsenite of lime, with nearly 

 a quarter of its Aveight of coloring matter. According to an 

 analysis of Dr. Collier it contains about forty-three per cent 

 of arsenic. It is a finer powder than the Paris green and 

 consequently remains in suspension longer. It may be used 

 in the same way, as a powder or in water. 



Kerosene- Emulsion. — Probably next to the arsenites — 

 London purple and Paris green — no single insecticide equals 

 in value the kerosene and soap mixture or kerosene emul- 

 sion. This insecticide kills by coming in external contact. 

 It is prepared by dissolving one-half a pound of soap in one 

 gallon of water. Remove from the fire when boiling hot, 

 add two gallons of kerosene, and agitate briskly for ten 

 minutes, when the whole should be a frothy, creamy mass. 

 On cooling, the emulsion will set in a gelatinous mass that 

 will remain indefinitely without separating, and at any time 

 may be diluted in w^ater to the desired strength and used. 

 In a good emulsion the particles of kerosene are so small 

 that when put in water they will not quickly rise to the sur- 

 face. A strength often recommended is secured by putting 

 one part of the emulsion, as above prepared, in nine parts of 

 water. Kerosene, used pure, will kill any insect or plant 

 to which it is applied. The object in making the emulsion 

 is two- fold : to lessen the expense of the application, and to 

 prevent injury to the plants to which it is applied for the 

 destruction of insects. It should always be applied with a 

 good force-pump. "It is doubtless better to throw all liquid 

 insecticides with force in spraying for injurious insects ; 

 with the kerosene emulsion it is absolutely essential to suc- 

 cess " (A. J. Cook). The kerosene emulsion is excellent in 

 destroying plant lice, scale or bark lice, many of the bugs, 

 and not a few caterpillars, grubs and slugs. Its great value 

 lies in its excellence as a specific against aphides or ])lant 

 lice. Pven the eggs can be killed by its use early in the 

 spring, just before they hatch. 



