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 SOg+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 
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) 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 
(DO 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. 
