296 



INSECTICIDAL MATERIALS AND PRACTICES 



Slake the lime, make a thin paste, and add the sulfur. Flowers 

 of sulfur or light or heavy sulfur flour may be used. The lime 

 should be fresh lump lime, free from dirt and grit, containing 90 

 per cent or more of calcium oxide and less than 5 per cent of 

 magnesium oxide. Stir thoroughly during the hour of cooking, 

 to break up the lumps of sulfur. Enough water should be added 

 at the start so that the evaporation will not leave the quantity 

 less than 50 gallons when the cooking is ended. If kettles are 

 used, 10 to 15 gallons additional will be needed, while with 

 steam none may be required. The kettles should be considerably 

 larger than the amount of wash to be made, to prevent loss of 

 material by boiling over. The clear liquid should be drawn off 

 into tight containers if to be kept any considerable time ; and 

 stored where there is no danger of temperatures much below 

 freezing. For use, test the clear solution with the hydrometer, 

 and dilute as indicated in the table : 



Dilutions of Concentrated Lime-Sulfur Solutions for Spraying 

 (N. Y. Exp. Sta.) 



3. Commercial concentrated mixtures. 



The lime-sulfur may be purchased in the concentrated form and 

 the trouble of making it avoided. The strength of the commercial 

 product varies considerably, and in order to compute the proper 

 dilution correctly the strength should be determined by means of 

 a hydrometer. Having determined the strength of the concen- 



