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alone and as a suitable medium for the application of the arsenites. I 

 wish to dispel the impression which seems to generally prevail, that 

 Bordeaux mixture is a very simple preparation, requiring- no great 

 amount of care to properly manufacture it. There are many little 

 points that have been discovered from time to time in connection with 

 the preparation of this fungicide, and these taken collectively are of 

 great value in simplifying and cheapening the work of spraying. 



It is found that much time is saved by preparing what may be called 

 stock solutions of both copper sulphate and lime milk. A stock solu- 

 tion of copper sulphate may be made by dissolving copper sulphate in 

 water at the rate of 2 pounds to a gallon. The most convenient way 

 to dissolve the copper sulphate is to tie it in a coarse sack and then 

 suspend the same in a barrel in such a way that it will be as near the top 

 as possible. The barrel is then filled with water, and the copper sul- 

 phate within the sack quickly dissolves, the solution sinking at once 

 to the bottom and the fresh water coming to the top to take its place. 

 If the copper sulphate is placed at the bottom of the barrel at once 

 the surrounding water soon becomes saturated with the chemical in 

 solution, and in this condition, being heavier than water alone, it 

 remains at the bottom, and in consequence prevents the further action 

 of the liquid above. 



If it is desired to make up a 50 gallon barrel of stock copper solu- 

 tion, 100 pounds of copper sulphate is weighed out, suspended in the 

 sack Avithin the barrel as already described, and the barrel is then 

 filled to a 50-gallon mark previously made. As soon as the copper 

 sulphate is dissolved the sack should be removed and sufficient water 

 added to bring the solution up to the desired quantity. A stock solu- 

 tion prepared in this way will last indefinitely, providing too much of 

 the water is not allowed to evaporate. 



In preparing a stock milk of lime, slake 100 pounds of fresh lime after 

 the fashion practiced by masons. When slaked place the paste in a 

 50-gallon barrel and then fill the latter with water. 



In preparing Bordeaux mixture from such stock solutions it is only 

 necessary to take a given quantity of each and mix them together. 

 Thus if the 50-gallon formula for Bordeaux mixture is adopted it will 

 be necessary to use 3 gallons of the stock solution of copper sulphate 

 and approximately 2 gallons of the stock lime preparation. The cop- 

 per sulphate solution should first be placed in a barrel and then nearly 

 enough water added to fill the latter. The lime milk should then be 

 added and the whole thoroughly stirred. Before using, the mixture 

 should be tested by the potassium ferrocyanide test; that is, a few 

 drops of the solution of the chemical in question should be added, 

 and if no change in color is noted the fungicide may be considered 

 perfectly safe. In case a reddish precipitate forms when the potas- 

 sium ferrocyanide is added lime milk should be stirred in until no 

 reaction takes place. 



