384 Eeport of the Horticulturist of the 



1 to 11 formula : One lb. copper sulphate ; f lb. lime, f i-esb 

 slaked ; 11 gallons water. 



Preparation of Bordeaux Mixture. — Dissolve the copper sul- 

 phate and dilute with from half to two thirds of the required 

 amount of water. Then add the lime in the form of thin white- 

 wash, straining it if necessary to keep out particles that would clog 

 the nozzle. Stir the mixture frequently and thoroughly as the lime 

 is being added. Finally dilute to the required amount. 



Dissolving the Copper Sulphate. — For practical operations the 

 copper sulphate may be dissolved in large quantities and kept on 

 hand as a stock solution, as advocated in Bulletin No. 67 of this 

 Station, p. 195. Such a solution should be kept covered to prevent 

 evaporation, which would increase its strength and finally cause the 

 copper sulphate to crystallize on the sides and bottom of the cask in 

 which it is kept. It appears that for all practical purposes a solution 

 containing two pounds of copper sulphate to one gallon of water 

 may safely be used for a stock solution. Thus, one hundred pounds 

 of copper sulphate dissolved in fifty gallons of water contains two 

 pounds for every gallon of the solution, so that one gallon of such a 

 solution contains enough copper sulphate to make twenty-two gal- 

 lons of Bordeaux mixture of the 1 to 11 formula, or fourteen 

 gallons of Bordeaux mixture of the 1 to 7 formula. 



If, instead of using the stock solution, copper sulphate is dis- 

 solved each time the mixture is prepared^ it is well to get the pul- 

 verized copper sulphate instead of the crystals, as that dissolves 

 more quickly. If the solution is wanted immediately, the copper 

 sulphate may be dissolved in hot water. If it is to be dissolved in 

 cold water, use a large amount of water and suspend it near the 

 upper surface of the water, in a basket, coarse sacking, or any other 

 receptacle through which water may pass readily. Copper sulphate 

 should not be dissolved in iron vessels, as it corrodes them very 

 rapidly. 



Buying Copper Sulphate. — It is best to buy copper sulphate in 

 sufficient quantity to get wholesale rates, for it may be kept from 

 season to season without injuring its value. 



Weighing and Straining the Lime. — When the mixture is used 

 in power spraying machines with stationary nozzles it should be run 

 through a sieve so as 'to take out all particles that might clog the 

 nozzles. When hand pumps are used straining will not be neces- 

 sary if care is used in pouring the lime. 



