—— 
PREPARATION OF BORDEAUX MIXTURE. 31 
PREPARATION OF BORDEAUX MIXTURE. 
The Bordeaux mixture used in the experiments was prepared accord- 
ing to the follbwing formula: 
5 pounds of copper sulphate (bluestone). 
5 pounds of fresh stone lime. 
50 gallons of water. 
For small lots dissolve the bluestone in 25 gallons of water, and in a 
separate vessel slake the lime by sprinkling it with 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 bag 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 be filled to the 50-gallon mark. Each gallon of this solution con- 
tains 1 pound of bluestone. Likewise 50 pounds of lime is placed in 
a barrel and slaked by slowly pouring water over it. While slaking 
keep it thoroughly stirred with a shovel, and continue 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 VIII, 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 about 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 platform. 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. Hach 
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 
