17 



•UeWnSV^ J?TX>r 



Method of Preparing^ Bordeaux Mixture for Large Operations. 



In large operationa stock solutions should always be used, as the time required to 

 dissolve the material is saved. 



Stock solutions. — These can be prepared of both the copper sulphate and the 

 lime. They may be made by dissolving copper sulphate in water at the rate of 1 

 pound per gallon, and lime in the same ratio, although a strength twice as great may 

 be used in warm weather. When stock solutions are on hand it is only necessary to 

 measure off the required quantity of each and dilute with water before mixing. In 

 preparing a stock solution of copper sulphate, a 50-gallon barrel may be filled about 

 two-thirds or three-fourths full of water; then a sack, or a box with perforations over 

 which copper wire has been tacked, containing 50 pounds of bluestone, should be 

 suspended in the upper part of the barrel and enough water added to till the barrel. 

 In from twenty-four to thirty-six hours this material will be entirely in solution, and 

 the sack or box may be removed. A slight stirring will insure the even distribution 

 of the bluestone, after which the solution is ready for use. 



The copper sulphate should be measured in a copper or granite-ware receptacle, 

 iron or tin vessels being 

 quickly destroyed by 

 either copper sulphate 

 or Bordeaux mixture. 



Use of an elevated 

 platform. — If possible 

 the dilution tank should 

 be raised so high on an 

 elevated platform that 

 the mixture can be con- 

 ducted by gravity di- 

 rectly into the spray 

 tanks beneath (fig. 5). 

 If a hillside is available, 

 it is much the most con- 

 venient Tjlace to do the ^^^' ^■~^^^^^°^^ '^'itt' elevated tanks for making Bordeaux mixture. 



work. The platform can be arranged with a roadway on its upper side so that the 

 lime and bluestone can be delivered there, while the spray tank is filled from the 

 lower side. 



The water supply.— A water supply of some sort is necessary; a tank filled by a 

 windmill pump and elevated so as to be a few feet above the dilution tanks is a great 

 advantage. Hose may be used to fill the dilution tanks, or an iron pipe with a spigot 

 may be placed over each tank. Each dilution tank should hold half the quantity it 

 is desired to make up at one time— that is, if a 200-gallon spray tank is to be filled 

 the dilution tanks must hold about 100 gallons each. There is no objection to add- 

 ing a few extra gallons of water, but it is better to have the tanks hold just the right 

 quantity. 



Methods of mixing- the solutions.— Either of two methods of mixing can be 

 employed: One in which the spray material is conducted directly from the dilution 

 tanks into the spray tank and actually mixed in this tank; the other in which a 

 mixing tank sits just below the dilution tanks and from which the spray, after 

 being mixed up, is conducted by gravity into the spray tank. In certain ways the 

 latter is more convenient than mixing directly into the tank, but unless the opera- 

 tions are somewhat extensive it will hardly justify the extra expense. In very large 

 operations, however, a separate mixing tank is recommended— or perhaps even two 

 of them side by side— so that batches of the mixture can be kept on hand for a few 

 moments awaiting the spray wagons. 



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