1/6 MAINE AGRICULTURAL EXPERIMENT STATION. 19OO. 



kept the bugs so reduced in numbers that they did no appreciable 

 damage to the vines, and the fourth application (August 10-11) 

 was unnecessary. The green was as usual somewhat difficult to 

 keep thoroughly and evenly suspended in the water. When 

 applied with lime at the rate of l /2 pound of Paris green and 

 two pounds of lime to the acre, the Paris green was more effec- 

 tive than when applied at the same rate with copper, (Bordeaux 

 mixture). The copper appeared to be distasteful to the bugs 

 and they would leave the thoroughly sprayed leaves for those that 

 had less copper and in this way they avoided the leaves with the 

 most Paris green. If vines are sprayed before the bug's have 

 made much growth, there is no difficulty in keeping them in 

 check, so they can do no harm, with two or three applications of 

 Paris green at the rate of Vi pound to the acre. Applied at this 

 rate with Bordeaux mixture or lime, there is no danger of burn- 

 ing the foliage. 



LOXDOX purple. 



London purple was first introduced in this country as an 

 insecticide in 1877. It is a waste product in the manufacture of 

 some dye stuffs and consists largely of arsenic, lime and the dye. 

 It is cheaper than Paris green, contains more arsenic and can be 

 more easily applied. 



Its composition is not so uniform, and it is more apt to injure 

 foliage so that on the whole Paris green has been preferred. It 

 was not used in the experiments here reported upon. Paris 

 purple and English purple are two preparations quite similar in 

 character to London purple. When an}- of the purples are used 

 as insecticides they should be used with two or three times their 

 weight of lime because of the soluble arsenic which they contain. 



paragrexe. 

 Paragrene is a patented article which claims to be free from 

 many of the objectionable features of Paris green. The manu- 

 facturers state that "Paragrene is a definite compound of arsenic, 

 sulphate of copper and lime and is made in such a way as to 

 neutralize whatever effect the acids, necessary to prepare the 

 ingredients, would have on plant life." It has recently been 

 analyzed by the California Agricultural Experiment Station 

 and found to contain 23.46 per cent of copper oxide and 40.60 



