580 NEW JERSEY AGRICULTURAL COLLEGE 



INSECTICIDZS. 

 Arsenate of Lead. 



Tliis material is meeting Avitli iin'iva?ed favor eacli year because 

 it may be safely used on so many plants on Avhieli no other arsenical 

 preparations can be applied, anU because of its adhesive qualities. 



As originally proposed it was formed by dissolving arsenate of 

 soda (four ounces) and acetate (sugar) of lead (eleven ounces),, 

 and cmnbining the solutions. Hoth of these materials are readily 

 soluble in water and when they were combined a very fine white 

 precipitate was fonned, which sank slowly to the bottom. This 

 precipitate was the arsenate of lead. It was not necessary to wait 

 for preci])itation, but, when the dissolved materials Avere united^ 

 the combined mixture was poured into the spraying tank, with a& 

 much water as wa-* vecdmnionded for the particular insect against 

 which it was required. 



A simpler way was to put the materials in the proper propor- 

 tions directly into the spraying tank with as much water as was 

 to be used, and then stir until all crystals were dissolved and 

 everything was thoroughly mixed. 



Very good results were obtained in this way, but various prac- 

 tical difficulties arose — the chemicals were not always of good 

 quality, and the resulting mixture was not a proper combination ; 

 the prices varied and the fanner often paid altogether too much 

 for his insecticide ; and lastly, the work of mixing in proper pro- 

 portion was too much fur many of those who would otherwise have 

 used it. 



The result was that the manufacturers of commercial insecti- 

 cides took tlie matter in hand and there are now v»n the market 

 a number of different brands, made by as many different firms^ 

 but very different in ai)p('arance, consistency and price. 



Li the municipalities in M-hich spraying work has been done^ 

 arsenate of lead is quite generally adopted because there is little 

 or no danger of injuring foliage through the carelessness of the 

 ignorant help that must be largely employed, and some of these 

 municipalities, in advertising for bids, received widely divergent 

 offers and some very questionable material. It became necessary 

 this spring to spray the elms of the College Campus to prevent 

 injury from the elm-leaf beetle, and in order to test some of the 



