30 CROP PEST COMMISSION OF 



ties over a fire. The boiler at a ginhouse or sawmill, if conven- 

 iently located, can be used as the source of the steam. Portable 

 boilers such as are used in sawing wood, or even steam feed cook- 

 ers, can be utilized. Where large orchards are to be sprayed, the 

 purchase of a boiler especially for the purpose is justified. In ar- 

 ranging such a plant its size will, of course, be dependent largely 

 upon the amount of the mixture required daily. Barrels should 

 be provided in which to boil the mixture, and these barrels should 

 be so placed upon a raised platform that the liquid when made 

 can be drawn off directly into the spray tank or barrel without 

 the labor of handling it with buckets. Steam from the boiler 

 should be conveyed through an iron pipe to or near the bottom of 

 each barrel, the steam supply to each barrel being controlled by a 

 globe valve conveniently located. If water pressure is available 

 a water pipe or hose should be run to each barrel to facilitate fill- 

 ing. If a well or stream is near the boiling plant a water supply 

 is readily obtained by use of a steam jet. 



The preparation of the mixture when steam is used differs in 

 no essential respect from the preparation in a kettle. A small 

 part of the water is brought to a boil in the barrel, the sulphur 

 paste added and this followed by the lime. With a good pressure 

 of steam it is not necessary to boil as long as where a kettle is 

 used. Boiling should always be continued until a greenish-yellow 

 tinge is imparted to the mixture. The particular color required 

 is soon recognized after a little experience. In case of doubt, the 

 boiling should be continued for at least 35 minutes or more, as 

 it cannot be boiled too much. In recommending this 35 minute 

 period of boiling, a violent boiling is meant. Mere simmering does 

 not bring about the chemical union of the lime and sulphur which 

 is essential to the success of the wash. 



The exact arrangement of the boiler, steam and water pipes, 

 barrels, etc., will vary according to the conditions under which 

 the plant is arranged. Figure 15, showing a small steam boil- 

 ing plant, will convey an idea of how such a plant may be con- 

 structed to good advantage. 



THE LIME-SULPHUR-SODA WASH. 



Upon private grounds and upon small premises in town or 

 city, many people do not like to go to the trouble of making the 



