SPRAYING 151 



fore very important, especially with hot lime, to 

 cool the mixture quickly by adding a few buckets 

 of water as soon as the lumps of lime have 

 slaked down. The intense heat, violent boiling, and 

 constant stirring result in a uniform mixture of 

 finely divided sulphur and lime, with only a very 

 small percentage of the sulphur in solution. It 

 should be strained to take out the coarse particles 

 of lime, but the sulphur should be carefully worked 

 through the strainer." 



In the use of this mixture it is often desirable to 

 add some insecticide, which should always be arsen- 

 ate of lead. Messrs. Scott and Quaintance, already 

 quoted, give the following suggestions regarding 

 the use of the arsenate of lead with the self-boiled 

 lime-sulphur: "Arsenate of lead is to be found on 

 the market both as a powder and as a putty-like 

 paste, which latter must be worked free in water be- 

 fore it is added to the lime-sulphur mixture. The 

 paste form of the poison is largely used at the rate 

 of about two pounds to each 50 gallons of the lime- 

 sulphur wash and is added, after it has been well 

 worked free in water, to the lime-sulphur spray pre- 

 viously prepared. As there are numerous brands of 

 arsenate of lead upon the market, the grower should 

 be careful to purchase from reliable firms. A de- 

 cided change in color will result when the arsenate 

 of lead is added to the lime-sulphur mixture, due to 

 certain chemical changes which, in the experience of 

 the writers, do not injuriously affect the fungicidal 

 and insecticidal properties of the spray or result in 

 injury to the foliage. 



"In large spraying operations it will be more con- 

 venient to prepare in advance a stock mixture of 

 arsenate of lead, as follows: Place 100 pounds of 

 arsenate of lead in a barrel, with sufficient water to 



