230 THE TREE DOCTOR 



Caution Use no more ammonia than is required to dissolve 

 the copper carbonate. Ammonia is variable in strength, and the 

 amount required must be tested in practice. 



To make copper carbonate : Dissolve ten pounds copper 

 sulfate (blue vitriol) in ten gallons of water, also twelve pounds 

 of carbonate of soda in same quantity of water. When cool, 

 mix the two solutions slowly, stirring well. Allow the mixture 

 to stand twelve hours and settle, after which pour off the liquid. 

 Add the same quantity of water as before, stir and allow to 

 stand the same length of time. Repeat the operation again, 

 after which drain and dry the blue powder which is copper 

 carbonate. 



4 Soda Bordeaux Mixture. 



Copper sulfate, 4 pounds. 



Commercial caustic soda, soda lye, (sodium 

 hydroxid) slightly in excess so that mix- 

 ture is alkaline according to strength, 

 1 Ib. 5 oz. to 1 Ib. 8 oz. by testing. 

 Water to make 50 gallons. 



To use instead of ammoniacal copper carbonate. 

 Warning In each case of change of grade or brand of com- 

 mercial caustic soda it will be necessary to test the strength. 

 Keep the mixture well agitated. 



To keep caustic soda After opening a container and test- 

 ing, weigh out the entire contents into portions such as are 

 needed to make a single spray tank of mixture ; put in Mason 

 jars under shelter, cover with a pint or so of water, and this 

 portion is ready to be used as needed. Opened packages of 

 caustic soda will absorb water and increase in weight on stand- 

 ing; unopened packages will usually keep for a year or more. 



5 Potash Bordeaux Mixture. 

 Copper sulfate, 4 pounds. 



Caustic potash, potash lye, (potassium hy- 

 droxid) 1 Ib. 5 oz. to nearly 1 Ib. 8 oz. as 

 necessary for slight excess. (See soda 

 Bordeaux.) 



Water to make 50 gallons. 



