8 77/6' Horticulturist" s Rule- Book. 



Arsenites (Paris green) continued. 



recommended is i part of poison to 50 of the diluent, but 

 if the mixing is very thoroughly done, i part to 100 or 

 even 200 is sufficient. 



Paris green is practically insoluble in water. When 

 mixed with water, the mixture must be kept in a constant 

 state of agitation, else the poison will settle and the liquid 

 from the bottom of the cask will be so strong as to do 

 serious damage, while that from the top will be useless. 

 For potatoes, apple trees and most species of shade trees, 

 i pound of poison to 200 gallons of water is a good 

 mixture. For the stone fruits, i pound to 300 or even 400 

 gallons of water is a strong enough mixture. Peach trees 

 arg very apt to be injured by arsenites, and for them the 

 mixture should be very dilute. In all cases, the liquid 

 should be applied with force in a very fine spray. It ap- 

 pears that at some seasons of the year foliage is more 

 liable to injury than at others. 



LONDON PURPLE. An arsenite of lime, obtained as a by- 

 product in the manufacture of aniline dyes. The compo- 

 sition is variable. The amount of arsenic varies from 30 

 to over 50 per cent. The two following analyses show its 

 composition: i. Arsenic, 43.65 per cent.; rose aniline, 

 12. 46; lime, 21.82; insoluble residue, 14.57: iron oxide, 

 1.16; water, 2.27. 2. Arsenic, 55.35 per cent.; lime, 

 26.23; sulphuric acid, .22; carbonic acid, .27; moisture, 

 5.29. It is a finer powder than Paris green, and therefore 

 remains longer in suspension in water. It is used in the 

 same manner as Paris green, but is sometimes found to be 

 more caustic on foliage. This injury appears to be due 

 to the presence of soluble arsenic. London purple should 

 not be used on peach trees. 



Either Paris green or London purple may be combined 

 with kerosene emulsion to give the material greater ad- 

 hesiveness to leaves and to increase its wetting power. To 

 100 gallons of the arsenite mixture, add i gallon of kero- 

 sene emulsion. 



The arsenites may be used in connection with various 



