FUNGICIDES, FOR PLANT-DISEASES. 47 



2. Into a vessel having a capacity of 2 quarts or more, 

 pour 1 quart of ammonia (strength 22 Beaumd), add 

 3 ounces carbonate of copper. Stir rapidly for a moment 

 and the carbonate of copper will dissolve in the ammonia, 

 forming a clear liquid. The concentrated liquid thus pre- 

 pared may be kept indefinitely. Dilute to 25 gallons. 



3. Carbonate of copper, 5 ounces ; ammonia (26), 3 

 pints ; water, 45 gallons. 



It is better to wet the carbonate before dissolving it. 



Blue Vitriol. See SULPHATE OF COPPER. 



Bordeaux mixture (copper mixture of Gironde). 1. Dis- 

 solve 6 pounds of sulphate of copper in 4 or more gallons of 

 water. In another vessel slake 4 pounds of quick lime ( 6 

 pounds air-slaked) in a small quantity of water. When 

 the latter mixture has cooled, it is poured into the copper 

 solution, care being taken to mix the fluids thoroughly by 

 constant stirring, and water is added to make about 40 gal- 

 lons of mixture. Stir before applying. Stronger mixtures 

 were at first recommended, but they are not now used. 

 This is the normal mixture. 



2. Powdered sulphate of copper, 12 pounds in 15-20 

 gallons of water ; lime, 8 pounds in 10-12 gallons of water. 

 When the materials are thoroughly incorporated with the 

 water, unite the two mixtures. 



3. Patrigeon Method. Dissolve 6 pounds copper in 

 water as for (1), and add milk of lime until a drop of 

 ferrocyanide of potassium (yellow prussiate of potash) 

 added to the mixture ceases to give a red-brown color 

 reaction. Used because the minimum amount of lime is 

 added, rendering the mixture more easy of application ; but 

 Bordeaux made in this way often injures fruit, particularly 

 in a wet season. 



The best way to dissolve the sulphate of copper is to 

 suspend it in a bag of coffee-sacking in the top of a barrel 

 of water. Use the pulverized sulphate. 



Bordeaux mixture may be applied in combination with 

 the arsenites. See Chap. I. (page 3). 



