MATERIALS USED 



The spraying materials employed consisted of Sulphate of 

 Iron and Sulphate of Copper. The strength of the Sulphate 

 of Iron solutions varied between 6 and 16 per cent, applied at 

 the rate of from 35 to 40 gallons per acre, while in a few cases 

 double that amount was applied by going twice over the 

 ground. In the case of the Sulphate of Copper solution the 

 strength varied from 2 to 3^ per cent, applied also at the rate 

 of 35 to 40 gallons per acre. 



The cost of the Sulphate of Iron was 6s per cwt., and that 

 of the Sulphate of Copper 40s. The cost, therefore, of a 10 

 per cent solution of Sulphate of Iron works out at about 2s. 2d. 

 per acre, and a 15 per cent solution at 3s. 3d. A 2 per cent 

 solution of Sulphate of Copper costs nearly 3s. per acre, and a 

 3 per cent solution about 4s. 3d. per acre. These materials can, 

 however, be had at a much cheaper rate, as the materials used 

 in our trials were of an unnecessarily high standard of purity 

 and were not purchased in the best market. 



The two substances were analysed in our laboratory. The 

 Sulphate of Iron was found to be practically pure, and the 

 Sulphate of Copper had a purity of 95.6 per cent. 



Inquiries show that Sulphate of Iron, sufficiently pure, can 

 be had at 4s. per cwt. and even for 3s. if purchased in quantity, 

 while Sulphate of Copper is quoted at a little over 30s. per 

 cwt. Consequently the cost per acre of a 10 per cent and a 15 

 per cent solution of Sulphate of Iron need not be greater than 

 is. 5d. and 2s. 2d. respectively. In the same way the cost per 

 acre of the Sulphate of Copper solutions would be reduced to 

 about 2s. 3d. and 3s. and 3d. respectively. 



METHOD OF SPRAYING 



The demonstrations were superintended in each case by 

 Mr. Haydon or Mr. Burton. 



The additional apparatus required includes a second bar- 

 rel of the same capacity (42 gallons) as the one to which the 

 pump is attached. A water-cart will also be required unless 

 water is immediately accessible. 



We will suppose a 10 per cent solution of Sulphate of 

 Iron is to be used. The procedure is as follows: 



