86 FUNGICIDES COMBINED WITH POISONS 
pounds of copper sulphate. Allow the copper sulphate completely to 
dissolve. If it is desired to hurry this part of the process, the sul- 
phate may be dissolved in hot water, using about 2 gallons and 
stirring well, and this may then be poured into the barrel and the 
latter filled up to 25 gallons. In another barrel slake 4 pounds of 
lump lime, adding more water and stirring well as the lime dissolves, 
until there are 25 gallons in the barrel. Then combine the sulphate 
solution and the limewater by dipping alternately from each into the 
spray tank. Or, the two may be poured slowly at the same time into 
the spray tank. It is essential that the mixture be thoroughly strained 
as it goes into the sprayer. 
On some plants the above formula for Bordeaux mixture is too 
strong, and should be altered to the following: copper sulphate, 2 
pounds; lump lime, 2 pounds; water, 50 gallons. The method of mak- 
ing is the same. 
Bordeaux mixture must be used as soon as prepared. If allowed to 
stand, it changes in composition. More lime may be added, and the 
material thus made use of, but this procedure is not recommended. 
Where this material is used in large amounts it is convenient to 
prepare separate stocks of copper sulphate solution and lime “ putty.” 
Kept separate, they will not deteriorate. Dissolve the copper sulphate 
in water at the rate of 1 pound of the sulphate to 1 gallon of 
water. One gallon of this concentrated solution will then equal 1 
pound of the sulphate. To prepare lime putty, place a known weight 
of lump lime in a flat trough and add just enough water to slake it. 
When it is all slaked, see that it is spread out evenly and cover with an 
inch or so of clear water, to exclude the air. It will be easy to figure 
out the number of square inches of putty to remove in order to have 
the equivalent of the desired weight of lump lime. Do not make the 
mistake of weighing out this putty and considering that a given weight 
is the equal of the same weight of lump lime. 
Arsenate of lead may be combined with diluted Bordeaux mixture ; 
but the better plan is to add it to the limewater before the final mixing. 
The poison should first be well mixed with water, so as to make a 
thin paste, in order that all of it may find its way into the final mix- 
