22 



found that the action of the simple arsenite of copper on the foli- 

 age of various plants used in the experiments was practically the 

 same as Paris green. Again in a subsequent bulletin'" Mr. Mar- 

 latt gives results of experiments with this and other arsenicals. 



ADVANTAGES OF GREEN AESENITE OVER PARIS GREEN. 



In addition to the comparatively low cost of manufacture the 

 principal advantage of green arsenite over Paris green is that, as 

 it is so much more finely divided, it remains in suspension in 

 water much longer. From experiments in the laboratory the 

 writer found that the ordinary crystalline Paris green, when 

 mixed with water at the rate of i lb. to 150 gallons, would sink 

 to the bottom of the jar in about five minutes, leaving the water 

 clear, while the green arsenite remained in suspension for over 

 two hours. 



It is because the green arsenite stays suspended in water so 

 much longer than Paris green, that it is more valuable as an 

 insecticide. Without doubt much of the failure to get good 

 results from Paris green is because of the diflBiculty of keeping it 

 evenly distributed through the tank. Unless the mixture is 

 almost constantly agitated, the Paris green sinks to the bottom 

 and is quickly drawn out by the pump, so that before the tank is 

 half empty, most of the poison is gone and the remainder of the 

 water contains so little Paris green as to be hardly worth applying. 



HOW TO USE GREEN ARSENITE. 



Green arsenite should be used the same as Paris green. For 

 ordinary purposes use one pound to from 100 to 150 gallons of 

 water with the addition of enough freshly slaked lime to make 

 the mixture slightly "milky" in appearance. Lime should 

 always be added, for, in addition to other uses, it prevents injury 

 to the foliage. It may be used with Bordeaux mixture in the 

 same manner as Paris green. 



PRICE PER POUND AND WHERE OBTAINED 



Green arsenite can be obtained from the Adler Color and Chem- 



"U.S. Dept. Agr., Div. Ent. Bui. 6, n. ser. 



