THE VARIOUS FORMS OF SULFUR 195 



and messiness of home preparation. And this is a great deal. 

 They are also very simple to use. 



On the other 'hand, the buyer pays considerably more for a 

 hundred gallons of spray by this method than he does to prepare 

 his own concentrate. 



2. Home-made Concentrate. This is the same material, in a 

 general way, as the commercial, but it does not run as high in 

 sulfur content. The great advantage of this form is that it can 

 be made up on the farm during the winter when work is slack 

 and when the labor expense is relatively small. The general 

 method of preparation is as follows, though formulas and 

 methods are still undergoing changes : 



Formula. 50 pounds rock lime, 

 100 pounds sulfur, 

 50 gallons water. 



It seems to be immaterial whether the sulfur is the flour 

 (finely ground) or the flowers, but the lime should be good 

 and should preferably have little magnesium in it. Slack 

 the lime in the kettle in which the cooking is to be done and 

 when the slacking is well started add the sulfur and mix 

 thoroughly. Then add enough water to make a thin paste. 

 Continue boiling vigorously until the sulfur is all dissolved, 

 which will usually take from forty-five minutes to one hour. 

 When the boiling is finished the concentrate may be put into 

 barrels and stored. If these barrels are perfectly tight and are 

 filled full, no other precaution is necessary than to cork up 

 tightly. If these conditions do not obtain then the concentrate 

 must be covered with oil. Any oil which will not injure the 

 trees and which does not take fire at the boiling point of water 

 will do. The various miscible oils are used with entire satisfac- 

 tion. There is sometimes considerable sediment, but this does 

 not seem to be a serious objection. 



The proper degree of dilution either with the home-made or 

 the commercial, as measured by the specific gravity scale on the 

 hydrometer, seems to be about as follows: For San Jose scale, 

 blister mite, peach leaf curl and other spraying when trees are 



