260 A(jricultural Gazette of N.S. W. [Mar. 2, 1908. 



^lakf a paste in a wooden bucket of the earhonate of copper and a little 

 water. Add the anuuonia, which will dissolve the paste, and then dilute to 

 45 gallons. 



The first application should be made long before the leaves are half 



grown. 



Co[)per c;u-l)onate is obtainable from wholesale chemists, but is not stocked 

 in very large quantities, as there is little demand for it. The price is Is. 'Jd. 

 per lb., in 7 lb. lots. 



Owing to the difficulty of obtaining carbonate of copper in smaller towns, 

 as well as the high jirice usually charged for it, the Department recommends- 

 that the fruitgrowers prepare it. 



The following is the method given by Pierce : — 



" In a barrel dissolve 6 lb. of copper sulphate in -i gallons of hot water. 

 In another wooden vessel dissolve 7 lb. of washing soda 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 cold pour the soda, 

 solution slowly into the copper solution. As soon as bubbles cease to rise fill 

 the barrel with water, stir thoroughly, and allow the mixture to stand over 

 night to settle. The next day syphon off all the clear li(juid from the top 

 with a piece of hose, fill the barrel with water, stir thoroughly, and allow it- 

 to stand a second night. Syphon off the clear liquid the second day, fill the 

 barrel with water, stir, and syphon ort the clear licpiid once more the third 

 day. Now pour out 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 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 -Go lb. of cojiper carbonate." 



The cost of preparing carbonate of copper by this method will depend on 

 the cost of the sulphate of copper and the sodium carbonate (sal-soda or 

 washing soda). The present price of copper sulphate is 3d. per lb., and 

 washing soda 2d. per lb. ; tlms the cost will be as follows : — 



s. d. 

 G lb. of Copi)ei- Sulphate, @ 3d. ... ... ... 1 G 



7 lb. of .Sodium Carbonate @ 2d. ... ... ... 1 2 



2 8 

 As these ingredients will make 2*65 lb. of the carbonate of copper, the cost 

 will be apj)ro.\imately Is. per lb. 



The advantages of making it at the orchard are twofold; firstly, the 

 suljihate is obtainable almost anywhere, tlui.s saving delay, and secondly, the 

 cost is less. 



Very little time is taken up, as there is no continuous stirring or watching, 

 as is the case with some mixtures. 



