SPRAYING 



239 



it may cause the mixture to be efficient for a longer period and 

 thus lessen the danger of injury. 



Suspend 3 pounds of copper sulphate, or bluestone, in 2 5 gallons 

 of water until it is dissolved. Slake 3 pounds of the best quick- 

 lime that can be obtained, taking care not to use an excess of water ; 

 then add enough water to make a whitewash. Strain to remove 

 lumps, and add sufficient water to make 25 gallons. Pour the two 



Fig. 108. Spraying equipment 



Elevated platform, at the right, for preparing Bordeaux mixture. The larger tank on the 

 higher platform is for water storage. Types of spray rigs. (University of Maine) 



solutions into a barrel, and test to find out if any free copper is 

 present. To make the test, proceed as follows : 



1 . Take a portion of the clear fluid that is left on top after the 

 sediment settles and put in a saucer. Blow gently over the surface. 

 If a thin white pellicle forms over the top, there is lime enough. 



2. Immerse a newly filed piece of steel for a minute or so. If 

 it becomes coated with copper, more lime is required. 



Whale-oil soap. Whale-oil soap, which has the peculiar charac- 

 teristic of remaining liquid when cold, has greater penetrating 

 powers than other soaps and is more fatal to insect life. The 

 formula is 1 pound of soap to 2 gallons of water, the soap being 



