GENERAT. INFORMATION 2 



"/ 



12 lbs. copper sulphate. 

 10 lbs. lime (freshly burnt). 

 100 gallons water. 

 Three wooden vessels are necessary for the 

 proper mixino- ; two small and one double their 

 size — paraffin barrels answer well for small quan- 

 tities. Powder the copper sulphate, put in a piece of 

 sacking, and dissolve in half the water in one of the 

 small vessels. Slake the lime in the other small 

 vessel with the remainino- water. When the lime 

 wash is cooled, pour the contents of the two vessels, 

 after stirrino- both at the same time into the lar^e 

 receptacle. The resulting solution should be tested 

 in one of the following ways : for if too much h'me 

 be present it is useless as a fungicide, if too little, it 

 is dangerous to the crop. 



{a) Ferrocyaiiide Test. — Add one drop of a 

 solution of potassium ferrocyanide to the 

 mixture ; if the colour of the drop changes 

 to a dark, reddish brown, more lime is 

 necessary, if no change in colour, the mix- 

 ture is safe to apply. 

 {[)) Hold a clean knife blade, or other briglit 

 surface of steel, in the mixture for one 

 minute, if on removal it is clean, the solu- 

 tion is safe to use ; if copper is deposited 

 on the surface of the blade, more lime 

 must be added. 

 [c) Litj?ms Paper, — After the liquid has settled 



