PICKERING SPRAYS. 6 



actual weight of pure lime (calcium oxid) and the approximate 



volume of clear limewater which would contain this lime are also 



given in each case. 



Formula A (4 CuO, S0 3 ). 



Proportions required: Crystallized copper sulphate 1, lime 0.169 

 (6:1); or copper sulphate 1 ounce, 1 limewater 134 ounces. 2 



REACTION. 



(A) 10 CuS0 4 + 7.5 CaO = 10 CuO, 2.5 S0 3 +7.5 CaS0 4 

 (A')10 CuO, 2.5 S03+3.75 C0 2 = 3.75 (CuO) 2 , C0 2 +2.5 CuS0 4 



This formula represents a 25 per cent re-formation of copper sul- 

 phate. 



Formula B (5 CuO, S0 3 ). 



Proportions required: Crystallized copper sulphate 1, lime 0.18 

 (5.56:1); or copper sulphate 1 ounce, 1 limewater 143 ounces. 2 

 t 



REACTION. 



(B) 10 CuS0 4 +8 CaO=10 CuO, 2 S0 3 +8 CaS0 4 

 (B')10 CuO, 2 SO3+4 C0 2 = 4 (CuO) 2 , C0 2 +2 CuS0 4 



This formula represents a 20 per cent re-formation of copper 



sulphate. 



Formula C (10 CuO, S0 3 ). 



Proportions required: Copper sulphate 1, lime 0.203 (5:1); or 

 copper sulphate 1 ounce, 1 limewater 161 ounces. 2 



REACTION. 



(C) 10 CuS0 4 + 9 CaO = 10 CuO, S0 3 +9 CaS0 4 



(C y ) 10 CuO, SO3+4.5 CaO = 4.5 (CuO) 2 , C0 2 +CuS0 4 



This formula represents a 10 per cent re-formation of copper 



sulphate. 



Formula D (Ordinary Bordeaux Mixture). 



Proportions required: Equal weights of copper sulphate and lime; 

 or copper sulphate 1 ounce, 1 limewater 800 ounces. 2 



REACTION. 



(D)10 CuS0 4 +44 CaO = 10 CuO, S0 3 , 3 CaO +9 CaS0 4 +32 CaO 

 (D') 10 CuO, S0 3 , 3 CaO +7.5 C0 2 = 



4.5 (CuO) 2 , C0 2 + 3 CaC0 3 + CuSO* 



This formula represents a 10 per cent re-formation of copper 

 sulphate. 



1 Avoirdupois. 2 Fluid imperial ounces. 



