SPRAYING EXPERIMENTS. 65 



Slack the lime carefully and acid water to make twenty-five gal- 

 lons. Dissolve the copper sulphate in water and dilute the so- 

 lution to make twenty-five gallons. Mix the two solutions to- 

 gether by pouring first a pailful of one and then of the other 

 into a third vessel. Never mix the solutions while warm. The 

 Ume is best slacked a day or two before being used, so that it 

 will be perfectly cool. Strain the mixture as it is poured into 

 the spray barrel or tank. Made in this way, Bordeaux mixture 

 should remain in suspension in the water for some hours, but if 

 the solutions are mixed together in concentrated form and then 

 diluted by adding water to make up the fifty gaUons or if they 

 are mixed while hot, the resulting mixture settles very quickly, 

 making it difficult to distribute it evenly in spraying. Bordeaux 

 mixture should be used while fresh. After it has once settled 

 it can never be made to stay in suspension well again. The 

 copper sulphate solution can be kept indefinitely, and the lime 

 will also keep well if the water is not allowed to evaporate, leav- 

 ing it dry. When the two ingredients are brought together, 

 however, the mixture should be used within a fevv hours at 

 most. It is often desirable to make up stock solutions of the 

 lime and copper sulphate in sufficient quantity to last through- 

 out the season. When this is practiced it is common to dissolve 

 the copper sulphate at the rate of one pound to the gallon of 

 water and to make up the lime mixture in the same way, aUow- 

 ing one pound of stone lime for each gallon of water. The lime 

 and copper sulphate can then be diluted and mixed at any time, 

 just previous to spraying. 



If desired, Paris green or any other of the arsenic poisons 

 may be added to Bordeaux mixture to kill the apple worm and 

 other insects which may feed upon the fruit or leaves of the ap- 

 ple. It is especially important to add poison with the Bordeaux 

 mixture at the second spraying for scab — soon after the blos- 

 soms have fallen. Use from one-fourth to one-third pound of 

 Paris green to 50 gallons of Bordeaux mixture. 



Copper sulphate solution and Bordeaux mixture should never 

 be kept in iron receptacles, but will not injure wooden, earthen, 

 copper, or brass vessels. The spray pump should always have 

 brass working parts — valves, cylinders, etc. 



