Bordeaux mixture is a cure for almost every variety of plant disease. It consists of sulphate of copper (blue vitriol) and lime, diluted with water. The principal use of the lime is to make the mixture stick to the plant and to render the copper sulphate less caustic, and one thorough spraying, if rain does not come for a day or two, will cling to the plant for a couple of weeks. This mixture can be safely used even before there is any sign of disease, and it then acts as a preventive. But where disease is severe, apply it every few days, because the new leaves and shoots offer so many breeding places for the disease spores. To make 12 gallons of Bordeaux, use one pound of copper sulphate and one pound stone lime. Be sure to use wooden vessels, as vitriol eats tin; an oil barrel, sawed in halves, makes good tubs for dissolving the vitriol and slaking the lime. Put one to one and a half gallons of water in the tub and hang the vitriol over night in a piece of burlap, which just touches the water. Slake the lime in the other tub by adding water as fast as the lime takes it up, and no faster. When both are properly dissolved, fill the spray barrel about one-eighth full of water and add the solution of vitriol. Add enough water to the lime barrel to make 2½ or 4 gallons and then strain the slaked lime into the spray barrel through a wire fly-screen or two thicknesses of potato burlap. Fill the barrel with water enough to make 12 gallons of mixture, and stir thoroughly for some minutes. If your spray has an “agitator” attachment, you need not trouble further, but if not, you must stir the mixture thoroughly every few minutes while spraying. Bordeaux mixture should be made fresh for each spraying, but the vitriol and lime may be prepared ahead in large quantities, if they are not mixed, and are kept covered to prevent evaporation. Thus forty pounds of vitriol may be dissolved in 40 gallons of water, and forty pounds of lime slaked in 40 gallons of water. Four gallons of each will make a basis for 50 gallons of Bordeaux mixture. The only disadvantage to Bordeaux mixture is that it discolors the plant, it being a “blue whitewash”; and those who object to the discoloration often use the ammoniacal carbonate of copper, rather than the sulphate. But this is not so sure a remedy, neither does it stick so well. It is made by dissolving an ounce of carbonate of copper in a pint of water and adding it to a quart of ammonia. If the ammonia is strong, use only enough to thoroughly dissolve the copper, otherwise it will injure the plants. Cork the mixture tightly and when wanted for use, add from 8 to about 20 gallons of water to each ounce of the copper. This is used principally on fruit that is nearly grown, or upon purely ornamental plants, to avoid discoloration.