FUNGICIDES, PREPARATION AND APPLICATION 435 



pare stock solutions, proceed as follows : dissolve the re- 

 quired amount of copper-sulfate in water in the proportion of 

 one pound to one gallon several hours before the solution is 

 needed, suspending the copper-sulfate crystals in a sack near 

 the top of the water. A solution of copper-sulfate is heavier 

 than water. As soon, then, as the crystals begin to dissolve 

 the copper solution will sink, bringing water again in contact 

 with the crystals. In this way the crystals will dissolve much 

 sooner than if placed in the bottom of the receptacle of water. 

 In case large quantities of stock solution are needed, two pounds 

 of copper-sulfate may be dissolved to one gallon of water. 



Slake the required amount of lime in a tub or trough. Add 

 the water slowly at first, so that the lime crumbles into a fine 

 powder. If small quantities of lime are used, hot water is 

 preferred. When completely slaked or entirely powdered, 

 add more water. When the lime has slaked sufficiently, 

 add water to bring the mixture to the proportion of one pound 

 of lime to one gallon of water. These stock mixtures should 

 not be allowed to dry out and should be kept covered. 



To make the bordeaux, use five gallons of stock solution of 

 copper-sulfate for every fifty gallons of bordeaux required. 

 Pour this into the tank. Add water until the tank is about 

 two-thirds full. From the stock lime mixture take five gallons 

 of the thoroughly stirred lime-milk for each fifty gallons of 

 the mixture required. Dilute this a little by adding water, 

 and strain into the tank. Stir the mixture and add water to 

 make the required multiple of fifty gallons. Experiment sta- 

 tions often recommend the dilution of the copper-sulfate solu- 

 tion and the lime mixture each to one half the required amount 

 before pouring together. This is not necessary, and is often 

 impracticable for commercial work. It is preferable to dilute 

 the copper-sulfate solution. One should never pour together 

 the strong stock mixtures and dilute afterwards. Bordeaux 

 mixture of other strengths as recommended is made in the 



