236 THE APPLE 



minutes. The time at which the cold water should be added to 

 cool the mixture and prevent further action varies according to the 

 activeness of the lime. If the mixture remains hot too long, an 

 excess of soluble sulphur will be formed, which is injurious to 

 peach foliage. It is therefore very important that all action should 

 be stopped at the proper time, which, generally speaking, is just 

 as soon as the apparent action of the lime has ceased. 



The final mixture should consist of finely divided lime and sul- 

 phur with only a slight amount of soluble sulphur. This finely 

 divided lime and sulphur will settle very quickly, leaving a clear 

 solution above. The clear solution should be orange yellow in 

 color, due to the soluble sulphur it contains. If the clear solution 

 presents a distinctly red appearance, similar to that of concentrated 

 lime-sulphur, it indicates an excessive amount of soluble sulphur, 

 which may injure the tender foliage. A few practical tests will 

 enable anyone to prepare this spray and to recognize mixtures 

 having a dangerous amount of soluble sulphur. 



It is best to apply the self-boiled lime-sulphur as soon as possible 

 after it has been prepared, although it may be kept for a time 

 without loss. The mixture should be thoroughly stirred, and well 

 strained when transferred from the barrel to the spray tank. It is 

 very important that the outfit used to apply this spray be provided 

 with an agitator that will stir the mixture thoroughly, because of 

 the large amount of heavy sediment contained. Thorough agita- 

 tion is especially important when the self-boiled formula is used 

 in combination with arsenate of lead. 



Concentrated lime-sulphur, commercial. The commercial lime- 

 sulphur can be had from practically all the insecticide companies, 

 and varies in price according to the amount purchased. In barrel 

 lots (50 gallons) it costs about $9.00 delivered ; in half barrels, 

 20 cents per gallon ; in ten-gallon lots, 2 5 cents ; in five-gallon 

 lots, between 30 and 40 cents ; and by the gallon, from 50 to 

 75 cents. In ten-barrel lots it will cost about $8.25 per barrel. 

 This material tests from 32 to 35 degrees Baume, and should be 

 clean and bright, without any sediment. Because of the varia- 

 tion the hydrometer should always be used so that the exact 

 strength may be known. When properly diluted, there is little or 

 no danger of burning apple-tree foliage. 



