EXERCISE XLI 



THE STUDY OF SELF-BOILED LIME-SULPHUR 



Material. Stone lime, flowers of sulphur. 



Apparatus. Granite kettle, stirring-rod. 



Self-boiled lime-sulphur differs from the lime-sulphur wash in 

 Exercise XL chiefly in that there is no artificial heat applied 

 and all of the cooking that the solution undergoes is done by the 

 heat generated by the stone lime in slaking. This is used only 

 as a summer spray, and is proving very satisfactory for use on 

 the peach against the scab and brown rot. The formula that is 

 most often used is 



Flowers of sulphur 8 ib. 



Stone lime 8 Ib. 



Water 50 gal. 



Laboratory formula. Weigh out two and one-half ounces of 

 the flowers of sulphur and two and one-half ounces of stone 

 lime. Place the lime and the sulphur in a granite vessel and add 

 enough cold water to slake the lime, stirring constantly to pre- 

 vent burning. Cover the granite kettle, so as to retain as much 

 of the heat as possible. Watch the mixture closely, and as soon 

 as an orange-colored liquid begins to gather on the surface add 

 enough more water to make a gallon. Do not use hot water 

 or allow the mixture to stand after the lime is slaked or before 

 dilution. In this spray we do not want soluble sulphides to form, 

 because these will injure the foliage as well as the fruit. How 

 does this solution differ from the one in Exercise XL ? Describe 

 the color of each solution and note any differences. Why should 

 cold water be used instead of hot water ? Why is the prevention 

 of the formation of soluble sulphides especially important ? 

 Discuss. 



REFERENCE : 



Special Bulletin No. 61, Michigan Agricultural Experiment Station. 



[144] 



