242 CHEMICAL FERTILIZERS 



burnt quicklime with a little water, diluting to 5 galls, and 

 pouring into 35 galls, of copper sulphate solution, made 

 as above. As quicklime varies in composition, this recipe 

 is not always satisfactory and some manufacturers prepare 

 a paste ready made for the use of farmers. Many difficulties 

 are encountered in the manufacture and use of such 

 mixtures and it appears to be more generally useful to employ 

 the Burgundy mixture which is easy to make on the farm. 

 The labour on the farm can be reduced if the correct quantities 

 of copper sulphate and washing soda are weighed out into 

 small sacks and sold ready for use. As fruit trees are apt 

 to be scorched by Burgundy mixture, a special Bordeaux 

 mixture is preferred ; for this purpose the amount of copper 

 sulphate in the above recipe is reduced to 3 Ibs. and the 

 lime increased to 3 Ibs. Some users prefer to pour the 

 copper sulphate solution into the milk of lime. When 

 copper sulphate is mixed with basic substances, copper 

 hydrate and basic copper sulphate are formed, the relative 

 proportions depending on the amount of basic substance 

 added. In the case of Burgundy mixture, the presence 

 of carbonic acid causes a basic carbonate to be formed, 

 which slowly reacts with the carbonate left in solution, 

 ultimately forming green crystalline malachite. Treacle and 

 other adhesives are sometimes used in conjunction with 

 any of the above copper sprays. The introduction of soap 

 into such mixtures causes a great change in their chemical 

 and physical properties since copper soaps are formed. 



Ammonia and Copper. For horticultural purposes 

 mixtures containing copper sulphate and ammonia are often 

 favoured. For spraying chrysanthemums and other flowers 

 a green adherent compound is not suitable. As mixtures 

 containing copper and ammonia are not readily made on 

 the spot, it is better to purchase a ready-made mixture. 

 A good recipe is 10 Ibs. of copper sulphate, 15 galls, of 

 water and i-| galls, of ammonia (*88o gravity). Such a 

 stock solution must be diluted so that one pint makes 

 2-4 galls, for spraying the flowering plants : a dilution of 

 from i : 16-1 : 32. 



