Copper sulphate, 5 pounds. Lime (unslacked), 5 pounds. Water, 50 gallons. Dissolve the copper sulphate in two gallons of water, place it in barrel No. 1 and add water to make twenty-five gallons. Slack the lime, reduce it to a very thin paste, place it in barrel No. 2 and add water to make twenty-five gallons. To mix the solutions of lime and copper sulphate, dip a bucketful from each barrel, and pour together into the barrel of the spray pump. _The two mixtures should flow together as they are poured into the barrel._ This is one of the secrets of making a first-class mixture. The best arrangement is to have the barrels, Nos. 1 and 2, elevated, and use a piece of rubber hose to run the liquids into the pump barrel. If a large amount of spraying is to be done, a somewhat different policy should be pursued. Too much time would be taken up in preparing the ingredients in small quantities. Instead, large amounts of copper sulphate should be dissolved and large quantities of lime slacked beforehand. This may be done as follows: In a fifty-gallon barrel place about forty gallons of water. Put one hundred pounds of copper sulphate in a sack and suspend it in the water. As soon as dissolved, fill up to the fifty-gallon mark. When well stirred, each gallon will contain two pounds of copper sulphate. Each time some of the solution is dipped out, the height of the remaining portion should be marked on the inside of the barrel. Before taking more of the solution out of the barrel, any amount of water lost by evaporation should be made good by filling up to the mark last made. As soon as procured the lime should be slacked, placed in a barrel and kept covered with an inch or two of water. In this way it can be kept indefinitely. To prepare Bordeaux mixture from these stock solutions, dip out two and a half gallons of the copper sulphate solution, place it in barrel No. 1 and dilute to twenty-five gallons. From the slacked lime take fifteen pounds, or thereabouts, to allow for the water it contains, reduce to a thin paste, place it in barrel No. 2 and add water to make twenty-five gallons. Pour the contents of barrels Nos. 1 and 2 together, as already directed. _Tests_: If free copper be present, severe injury may be done to the foliage or other tender parts of the plants. Sufficient lime should be added to neutralize it. Dip out a small quantity in a porcelain saucer or shallow bowl, and holding it on a level with the mouth, blow the breath gently into it. If a thin pellicle forms on the surface, more lime must be added. Add and test until it does not form. An excess of lime will not hurt.