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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 within the barrel as already described, and the barrel is then 
tilled 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 stor-k 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. 
