New York Agricultural Experiment Station. 2)i7 



bination with other substances which will render it insoluble, since 

 it is very injurious to foliage when in a soluble form. It will be seen 

 then that white arsenic and water or white arsenic dissolved in sal- 

 soda and water without lime are -unsafe combinations to use. 

 Arsenite of lime is a safe form in which to use arsenic since it does 

 not dissolve in water. There are two methods of preparing arsenite 

 of lime as follows : 



White arsenic i pound. 



Freshly slaked lime 2 pounds. 



Water 2 gallons. 



Boil for twenty minutes or more, then dilute with 400 gallons of 

 water. To insure having a safe spray add 2 pounds of lime paste to 

 every 50 gallons of spray mixture. This formula is not considered 

 as reliable as the one given below since it is difficult to tell when all 

 of the arsenic is dissolved and combined with the lime and if pre- 

 pared in large quantities the arsenite of lime will gradually settle 

 into a compact mass that will not readily mix with water. 



ARSENITE OF SODA. KEDZIE FORMULA, 



White arsenic 2 pounds. 



Sal-soda 8 pounds. 



Water 2 gallons. 



Boil until the arsenic is all dissolved, which will take about fifteen 

 minutes. Replace the water that has been lost in boiling as other- 

 wise some of the material will crystallize upon cooling; then place 

 in an earthen vessel where it can be kept as a stock solution. One 

 pint of this stock solution is equivalent to four ounces of paris green 

 and is used in the same way ; that is, one pint of the stock solution, 

 two pounds of freshly slaked lime and 45 gallons of water, or one 

 pint of the stock solution to 45 gallons of bordeaux mixture. It 

 must not be used alone, but lime must be added. It then forms 

 arsenite of lime. 



