164 EXPERIMENT STATION EECORD. 



No. 53, and arsenite of lime. These insecticides were used in four dif- 

 ferent strengths, i lb., i; lb., 1 lb., and 1^ lbs. per barrel of 48 gals. 

 Orchard application of these sul)stances was made on June 10, while 

 potatoes were sprayed on Jul}" K) and 17. 



Tables are presented showing the comparative effects of the 4 dif- 

 ferent strengths of the different insecticides upon foliage. A test 

 was made of the insecticide value of these materials on potatoes. 

 Two strengths of the substances were used, i lb. and ^ lb. to a bar- 

 rel of 48 gals. Both strengths of Paris green, Paragrene, XX, and 

 Green Arsenoid killed all the potato beetles, and nearh' all the beetles 

 were killed b}" both strengths of Pink Arsenoid, Green Arsenoid No. 

 53, and Green Arsenite. 



Brief notes are given on the composition of various arsenical poisons. 

 The authors find that no damage is done to foliage in spraying with 

 i lb. of the ordinary arsenites to the barrel, provided less than 3i per 

 cent of soluble arsenic is present in the insecticide. 



Attention is called to the importance of the specific gravit}' of vari- 

 ous arsenical poisons in spraying. Considering the specific gravity of 

 Paris green to be 10, other insecticides compare in weight as follows: 

 Green Arsenite 10, Pink Arsenoid 9, Paragrene 7, Green Arsenoid 7, 

 XX 4, Green Arsenoid No. 53, 4. Equal amounts of these arsenites 

 shaken in water follow nearly the same order in settling, Paris green 

 being first, and Green Arsenoid No. 53 last. Paragrene, Green Arsen- 

 ite, Green Arsenoid, and arsenite of lime are all recommended as 

 arsenical sprays. The comparatively high percentage of soluble arsenic 

 in Green Arsenoid No. 53 makes this substance objectionable. 



Experiments were conducted to determine the effect of copper car- 

 bonate and potassium sulphid on the foliage of Japanese plums, cop- 

 per carbonate being used at the usual strength and potassium sulphid 

 at the rate of 1 oz. to a gallon of water. Both substances were rather 

 more injurious to the foliage than Bordeaux mixture. Where these 

 substances were used too freely, the shot-hole effect upon the foliage 

 was very noticeable. 



The general conclusions of the authors may be stated as follows: 

 The mechanical mixture of kerosene and water will probably displace 

 kerosene and soap emulsion. In spraying with kerosene and water, 

 earl}' spring or late fall seem to be the preferable seasons. Paragreiie, 

 Green Arsenite, Green Arsenoid, and arsenite of lime are equal if not 

 superior to Paris green. Unless lime is added, the simple solution of 

 capper sulphate, 4 oz. to the barrel, can not be used without injury to 

 the foliage. 



The nature and use of certain insecticides, J. L. Phillips and 

 H. L. Pkice {Vuyinia Sta. Bui. 97., pp. 7-26). — The authors describe 

 and give brief notes on the common arsenical, contact, and tracheal 

 insecticides and on the methods of their application. Experiments 



