358 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



III. Copper Sulphate Solution. 



Copper sulphate (blue-stone)* . . . 1 lb. 



Water 15-25 gallons. 



Preparation. — I. Iron sulphate readily dissolves in water. 



II. Put the iron sulphate in a wooden (not metal) vessel and pour 

 upon it the sulphuric acid ; add the water by degrees, commencing as soon 

 as the acid has been poured on. 



III. Copper sulphate is best dissolved by placing in a loosely woven 

 bag and suspending in water in a wooden vessel. 



Uses. — These sprays are for use in winter only, and are to be used on 

 trees which have been attacked by a fungus in order to destroy resting 

 spores. The iron sulphate solutions are very disagreeable to use owing to 

 the readiness with which they burn clothing, &c. The weaker copper 

 solution should be used in spraying peach trees and others with tender 

 shoots. The copper sulphate may be used in combination with paraffin 

 and caustic soda (Woburn Winter Wash (B) see page 350). 



B. Copper Sprays. 

 L Bordeaux Mixture (Normal Solution). 





Copper sulphate 



. 6 1b. 





Quicklime 



. 4 lb. 





Water ....... 



. 40 gallons. 



n. 



Bordeaux Mixture (Woburn Recipe). 







Copper sulphate 



. 10 oz. 











Water to make up to 



. 10 gallons. 



in. 



Soda-Bordeaux Mixture. 







Copper sulphate 



. 4 lb. 





Caustic soda 



. 1 lb. 4 oz. 





Water 



. 50 gallons. 



IV. 



Ammoniacal Copper Carbonate. 







Copper carbonate ..... 



. 5 oz. 





Strong ammonia (-880) .... 



. 3 pints. 





Water 



. 45 gallons. 



Preparation. — I. Dissolve the copper sulphate in the manner de- 

 scribed above in about 20 gallons of water in a wooden vessel. Slake 

 the quicklime in another vessel, adding water gradually at first until the 

 lime has crumbled to a powder, then in greater quantity, so as to form a 

 milk. When cold, and not before, strain this through a piece of coarse 

 cloth, adding it to the copper sulphate solution, constantly stirring mean- 

 while. The addition of the milk of lime should be stopped when, on adding 

 a drop or two of a solution of potassium ferrocyanide to a little of the 

 mixture in a white saucer, no red colour is produced. The mixture is 

 not fit for use until the addition of a few drops of ferrocyanide of potassium 

 produces no red colour, and it is unwise to add more lime than is required 



* The copper sulphate employed in all these sprays should be of 98 per cent, 

 purity. 



