PREVENTIVE AND COMBATIVE MEASURES. 69 



Bordeaux Mixture or Bouillie-lJordelaise, a .! to -i per cent, 

 solution of copper sulphate and lime. It is prepared by dis- 

 solving 6 lbs. of copper sulpliate in warm water, and placing 

 this mixture in a barrel capable of holding about 44 gallons ; 

 in another vessel slake 4 lbs. of fresh-burnt lime, and make it 

 up to a creamy whitewash with water ; strain the lime through 

 coarse canvas into the barrel of copper sulphate solution, fill 

 up with water, stir thoroughly, and the mixture is ready for 

 use. This mixture may be used either more concentrated, or 

 somewhat diluted. 



Ammoniacal Solution of Copper Carbonate. This may be 

 prepared directly by dissolving 5 oz. of copper carbonate in 

 enough water to form a thick paste ; dissolve this paste in 

 three pints of strong aqua ammonia (or as much as may be 

 necessary to effect complete solution) then dilute to 45 gallons. 

 If copper carbonate cannot be obtained, make it by mixing (a) 

 o lbs. of copper sulphate in 2 gallons of hot water, (b) 3^ lbs. 

 washing soda in 1 gallon hot water ; mix (a) and (b), add 

 water up to 10 gallons, stir up, and allow to settle ; pour off 

 the clear liquid, fill up again with water and allow to settle ; 

 on again pouring off the clear water a greenish sediment of 

 copper carbonate remains. This dissolved in as much aqua 

 auniionia as necessary, may be kept till required when it is to 

 be diluted at the rate of 1 pint to 2 gallons of water. 



Eau Celeste. Dissolve 2 ll)s. of copper sulphate in about 

 8 gallons of water ; when completely dissolved add 3 pints of 

 strong aqua ammonia and dihite to 45 gallons. This may be 

 used in a modified form. 



Fungicides like these are used chiefly against attacks of vine 

 mildew {Fcronospora viticola), potato disease {Phytophthora in- 

 festaufi) and Peronosporeae generally ; also for numerous other 

 leaf-diseases caused by various fungi. What the results of any 

 given experiment may be, is as yet difficult to say till more is 

 known of the effects of the reagents, the strength of the mix- 

 ture to be used, the kind of plant and its stage of development, 

 and other factors dependent on climate. The efficacy of a 

 fungicide lies less in its effects on the fungi actually present 



other Amei'ican literature, not the least important being " Bordeaux Mixture as 

 a Fungiciile," by D. C. Fairchild ; U.S. Anier. Bulletin, No. (j, 1894. In this 

 connection reference may also be made to E. G. Lodemann's account of the 

 "Spraying of Plants" (Macmillan, 1896). (Edit.) 



