THE TREE DOCTOR 231 



For use like soda Bordeaux mixture instead of ammoniacal 

 copper carbonate. 



Caution Prepare like soda Bordeaux, only after test of the 

 strength of the caustic potash. 



6 Copper Sulfate Solution. 



Copper sulfate, 4 pounds. 



Water to make 50 gallons. 

 Dissolve the sulfate as directed in Bordeaux I. 

 Caution The solution will injure foliage. It can be used 

 only before the buds open. 



7 Potassium Sulfid Solution. 



Potassium sulfid (liver of sulfur) 1 ounce. 



Water, 3 to 4 gallons. 



This solution will not remain unchanged. The potassium 

 sulfid must be kept in a well stoppered bottle. This may be 

 made by a similar process to that of No. 8. 



8 Sodium Sulfid Solution. 



Commercial caustic soda, 2^ Ibs. 



Flowers of sulfur, 5 Ibs. 



After solution, water to make 50 gallons. 



To make sodium sulfid at lowest cost : Place the caustic 

 soda in a metal vessel and add a little hot water. Then stir in 

 sulfur gradually, adding meanwhile hot water or applying heat. 

 The chemical reaction will generate heat. With its progress 

 the color will change from yellow to nearly brick red. No heat 

 is required after complete solution unless lime be added. Don't 

 add excess of water until the solution is effected. It may be 

 made in quantity with external heat and kept during a day as 

 stock solution. Excess of lime may be added with double or 

 triple portion of sulfur to make the possible equivalent of lime, 

 sulfur and salt solution. 



Caution This solution is prepared for application on dor- 

 mant trees. Care must be observed. 



Upon foliage, as of peach, a strength greater than 1 Ib. 

 caustic soda to 2 Ibs. sulfur is not to be recommended. 



