158 



to degrees of specific gravity, and the quantity of 

 solution required for a given volume of mixture. 



Table of Specific Gravity of Copper Solution. 



Twaddle's hydrometer is recommended as a con- 

 venient and sufficiently accurate instrument to use. 

 The cost is Is. 6d., and it can be obtained to order 

 to indicate the range of specific gravity required. 



Assuming that a field of two acres is to be sprayed, 

 if the stock solution is of 32 deg. Twaddle, about 24 

 gallons of this will be required, and can be drawn off, 

 to .be taken to the field. 



The copper dissolves more quickly if it is ground to 

 a powder. Sufficient copper may be dissolved at once 

 to supply several quantities of solution, but the water 

 must be measured so that the proper quantity for each 

 solution may be measured from it as required. Before 



