PREPARATION OF BORDEAUX MIXTURE. 31 



PREPARATION OF BORDEAUX MIXTURE. 



The Bordeaux mixture used in the experiments was prepared accord- 

 ing to the following fornuda: 



5 pounds of copper sulphate (bluestone). 

 5 pounds of fresh stone lime. 

 50 gallons of water. 



For small lots dissolve tiic l)luestone in 25 gallons of water, and in a 

 separate vessel slake the lime l)y sprinkling it v»ith water until a thick 

 paste is formed, and then dilute it to 25 gallons. Then pour the two 

 solutions together through a strainer into the spray tank or other 

 receptacle, a bucketful of each at the same time. When thoroughly 

 stirred, the mixture is ready for application. 



For extensive spraying, stock solutions should be prepared. Weigh 

 out 50 pounds of bluestone into a coarse ])ag and suspend it in a 

 50-gallon barrel of water near the top. The bluestone thus suspended 

 will usually dissolve within twenty-four hours, and the barrel should 

 then l)e tilled to the 50-gallon mark. Each gallon of this solution con- 

 tains 1 pound of bluestone. Likewise 5(> pounds of lime is i)laccd in 

 a barrel and slaked by slowly pouring water over it. While slaking 

 keep it thoroughly stirred with 'a shovel, and contiiuic to add water 

 enough to keep it from burning, but the mass should not be sub- 

 merged. When thoroughly slaked, dilute to 50 gallons. Each gallon 

 will then contain the equivalent of 1 pound of lime, provided it is 

 thoroughly agitated. Therefore, in order to make up 50 gallons of 

 the mixture take 5 gallons of the bluestone solution and 5 gallons 

 of the lime water. To prepare 200 gallons of the mixture for a spray 

 tank of that capacity 20 gallons of each constituent would be required, 

 but it should be remembered that these concentrated solutions should 

 be diluted before pouring them together. 



In order to save so much dipping, the mixing should be done on an 

 elevated platform, such as shown in Plate YIII, figure 1. The plat- 

 form shown in this illustration was constructed at the writer's sug- 

 gestion by Mr. W. H. Goodwin for use in the bitter-rot experiments, 

 as well as for his commercial work, and is al)Out 2 feet higher than 

 the top of the spray tank on the wagon. The stock solutions are 

 kept in 50-gallon barrels on the rear of the platform, and the two 

 dilution tanks, holding 100 gallons each, are placed at the front edge 

 of the i)latform. The bluestone solution is placed in one of these tanks 

 and the lime water in the other. Then each is filled with water up to 

 the 50, 75, or 100 gallon mark, as desired. A molasses gate (or faucet) 

 is fixed in a hole bored near the bottom of each tank, and this connects 

 with an open trough leading to the strainer in the spray tank. Each 

 of these gates is opened at the same time, and thus the two solutions 

 are allowed to run together into the spray tank. In this case the 

 16581— No. 93—06 3 



