81 



The lime should be fresh and slaked in small quantities as needed. 

 By mixing- a small quantity of water with the Paris g-reen until a paste 

 is formed it is much more easily distributed in the water. The lime 

 may be added to the water in the proper quantit3\ 



A good average strength of this solution is 1 pound of Paris green 

 to 150 gallons of water; but for trees with delicate foliage, such as 

 peach, it is advisable to use a much weaker solution. Many fruit 

 growers are using Paris green of the strength of 1 pound to 100 gal- 

 lons, with the addition of lime upon apple trees, without burning the 

 foliage. 



Scheeh^'^s green is a similar preparation to Paris green, but differs from 

 it in lacking the acetic acid. It is a liner powder than Paris green, is 

 much more easil}^ kept in suspension, and the cost is only about half 

 that of Paris green. There is but little of this insecticide manu- 

 factured and placed upon the market. 



London purple is a waste product in the manufacture of aniline 

 dyes. It contains a number of substances, of which the principal ones 

 are arsenic and lime. It ;s quite variable in composition, and is gen- 

 erally considered as being not so effective as some of the other arsen- 

 icals. For spraying it is now being replaced by the other poisons. 



Both Scheele's green and London purple are prepared for use in 

 spraying similarly to Paris green. 



WniTE ARSENIC COMPOUNDS. 



If white arsenic is used alone in spraying, it will seriously injure 

 the foliage of the trees by burning, but when combined with other 

 chemicals which prevent this burning, it forms the base of our most 

 efiecti\e sprays, any of which can be easily prepared by the fruit 



grower. 



Arsenite of lime. 



White arsenic pound . . 1 



Lime pounds. . , 2 



Water gallon . . 1 



The white arsenic and the lime are boiled together for not less than 

 half an hour in the required amount of water, as it is very difficult to 

 make the lime and arsenic combine. After the combination is com- 

 plete enough water is poured in to replace that lost by evaporation. 

 This solution may be kept as stock, and 1 pint of it used to every 

 40 or 50 gallons of water. It is advisable to add more lime to this 

 spraying solution in order that all danger of burning maj'^ be avoided. 

 Although this solution is by far the cheapest sprajdng material, there 

 is much danger of poor combination of the arsenic and lime, leaving 

 free arsenic, which will injure the foliage. In order that the lime 

 may more thoroughl}^ combine with the arsenic, soda has been used to 

 facilitate the combination. 



0511— No. 11—03 6 



