106 Journal of Agriculture, Vicfoiia. [11 Feb., 1918. 



requires stirring before using; this is usually done when running the 

 lime-water and blaestone into the spray pump or third vessel. 

 Bordeaux Mixture (French method) is made up as follows: — 



Materials. 



Copper Sulphate, 10 lbs. 



Fresh Quicklime, 5 lbs. 



Water, 50 gallons. 

 If the lime is of poor quality or air-slaked, more than 5 lbs. will be 

 required . 



Utensils. 

 A 60-gallon hogshead with one head removed ; pegs should be 

 inserted inside to show the 10 and 50-gallon levela 

 Two or three kerosene tins for boiling water in. 

 A tub or tin to slake the lime — capacity about 10 gallons. 

 An earthenware jug or jar — capacity 1 gallon. 

 A dipper — enamelled or painted inside and out. 

 A fine sieve. 



Some phenolphthalein testing paper. 

 A broom-handle to stir with 



Operations. 



Dissolve the copper sulphate in 5 gallons or so of hot water, make up 

 to 10 gallons with cold water. 



Remove one gallon of this solution in the earthenware jug or jar 

 and place it to one side. 



Add about 20 gallons of water to the copper sulphate solution in the 

 cask (this need not be measured). 



Slake the quicklime by adding small quantities of water at a time. 

 When slaked, add water sufficient to make about 6 or 8 gallons of milk 

 of lime. 



Pour this lime milk through the sieve into the bulk copper sulphate 

 solution, with brisk stirring until neutralized. Neutralization is shown 

 by the phenolphthalein paper turning pink. Stop adding lime milk as 

 soon as the test paper turns faintly pink. (The test paper can with 

 advantage be pinned to a small stick to avoid touching with fingers 

 wetted with lime water, which would result in misleading indications.) 



Add 1 gallon of Copper Sulphate solution previously wthdrawn; 

 stir thoroughly. 



Make up to 50 gallons with water, and stir again. 



The mixture is now ready for use. It should be used fresh, only 

 sufficient for the day's requirements being made up at one time. 



A stock solution of Copper Sulphate— 1 lb. to 1 gallon of water — 

 may be made up. This will keep indefinitely. Ten gallons of this 

 stock solution should be taken for each cask of mixture. Copper 

 Sulphate Solution must not be handled in iron or tin vessels unless 

 these have been very thoroughly painted or tarred both inside and out . 

 wood or enamel vessels are to be preferred. Copper Soda may be pre- 

 pared in similar manner to above, but about half as much again of soda 

 would be required, as in the case of lime. Phenolphthalein test paper 

 can be obtained from any chemist. It consists of strips of white filter 

 paper wetted with a 5 per cent, solution of phenolphthalein in methyl- 

 ated spirit and allowed to dry. 



