3 oz. carbonate of copper, 



1 lb. carbonate of ammonia, and 



50 gals, water. 



Mix the carbonate of copper witb the carbonate of ammonia, pul- 

 verized, and dissolve the mixture in 2 quarts of hot water. When 

 the}' are wholly dissolved, add the solution to enough water to make 

 the whole quantity fifty gallons. .This preparation has been found to 

 be better and cheaper than that made according to the original 

 formula, which is as follows : 



Dissolve 3 oz. 'carbonate of copper in 1 qt. aqua ammonia (22''B.)* 

 and add the solution to 25 gals, of water. 



Dr. Thaxter of the Connecticut Experiment Station suggests that 

 a very large saving may be made by preparing the carbonate of 

 copper by the following method, instead of buying it, as its market 

 price is much greater than that of the materials necessary for its 

 preparation. Take 2 lbs. of sulphate of copper and dissolve it in a 

 large quantity of hot water ; in another barrel or tub, dissolve 2i lbs. 

 of carbonate of soda (sal soda) in hot water. When both are dissolved 

 and cooled, pour the soda solution into the copper solution, stirring 

 rapidly. There will result a blue-green precipitate of carbonate of 

 copper, which must be allowed to settle to the bottom of the vessel. 

 Now draw off the clear liquid above the sediment, fill the vessel with 

 fresh water and stir up the contents thoroughly. After the copper 

 carbonate has once more settled to the bottom, again draw off the 

 clear fluid above. The carbonate may now be removed from the 

 vessel and dried, when it is ready for use. From the amoant of blue- 

 stone and sal-soda given above will be produced one pound of copper 

 carbonate, and the amount of each necessary to produce any given 

 amount of copper carbonate is easily calculated. 



Sulphate, of Copper is used in solutions of varying strength for 

 certain special cases. 



Sulphide of Potassium, known also as sulphuret of potassium or 

 liver of sulphur, has been found useful in the treatment of diseases 

 caused by those fungi known as Powder}' Mildews, especially on 

 plants grown under glass. It is ordinarily used in the proportion 

 of half an ounce of the sulphide to one gallon of water. 



Materials. For the convenience of persons who may wish to 

 purchase the necessary materials for the preparation of fungicides, 



*Dealers usually handle Ammonia water of a strength of 24° B. (=22.5^6 Ammonia) or of 

 26° B. (=26.r)5{ Ammonia). To reduce these to the required strength, 22° B. (=195i Ammo- 

 nia) , add four parts of water to ten of Aqua Ammonia of 26° or two parts of water to ten 

 parts of 24° Aqua Ammonia. 



