184 PEACH LEAF CUKL: ITS NATURE AND TREATMENT. 



water. In another wooden vessel dissolve 7 pounds of washing 

 or sal soda, in 2 gallons of hot water. The soda should be clear 

 (translucent), and not white and powdery, as it appears when air slaked. 

 When cool, pour the soda solution slowly into the copper solution. 

 As soon as })ul)bles cease to rise fill the barrel with water, stir thor- 

 oughly, and allow the mixture to stand over night to settle. The 

 next day siphon off all the clear liquid from the top with a piece of 

 hose, fill the barrel with water, stir thoroughly, and allow it to stand a 

 second night. Siphon off' the clear liquid the second day, fill the bar- 

 rel with water, stir, and siphon off' the clear liquid once more the 

 third day. Now pour the wet sediment from the barrel into a crock 

 or other earthen dish, strain out the excess of water through a cloth, 

 and dry slowly in an open oven, stirring occasionally, if necessary, to 

 prevent overheating. Prepared in this manner there should be 

 obtained, if none of the sediment in the barrel be lost, about 2.65 

 pounds of carbonate of copper. 



Owing most probably to the comparatively limited sale of carbonate 

 of copper, the market price has been and still remains too high. It 

 can rarely be obtained for less than 30 to 40 cents per pound, which is 

 from two to three times the cost to the grower whi^n it is prepared at 

 home. This condition reacts upon the manufacturer by causing 

 the grower to make his own carbonate, the mai'ket never feeling his 

 demand. With fungicides which the grower i^ unable to prepare the 

 conditions are different. His needs increase the demand in the market, 

 and increased demand tends ultimately to lower prices. 



The cost of copper car])onate when prepared by the grower will 

 depend upon the cost of copper sulphate and sal soda. Quotations of 

 March and April, 1899, placed copper sulphate at 5 cents per pound 

 by the barrel and sal soda at j% of a cent per pound in like quan- 

 tity. At these rates the grower should be able to i)repare the car- 

 bonate of copper at about 12.3 cents per pound. Quotations on larger 

 lots of sal soda and copper sulphate placed the price at y*^ of a cent 

 and 4f cents per pound, respective!}'. At these prices the raw mate- 

 rials for a pound of copper carbonate would cost about 11.8 cents. 

 These facts show that wholesale druggists and manufacturing chemists 

 could place the carbonate upon the mari^et at 15 or 20 cents per pound 

 and still make a good profit, even when liuying their sodium carbonate 

 and copper sulphate in the open market. If we go a step farther 

 back, however, we may see that the first cost of copper carbonate can 

 be greatly reduced below any figures here given. Ten-elevenths of 

 the cost is seen to depend upon the price of copper sulphate, and the 

 first cost of this I'atter depends upon the cost to the manufacturer of 

 sulphuric acid and copper. Both of these articles may be produced 

 as by-products of modern smelting processes. A firm at Blacksburg, 

 S. C, informs the writer that they employ gold-bearing pyrites for 

 the manufacture of sulphuric acid, the sulphur fumes being driven 



