AMMONIACAL PHOSPHATE OF SODA. 215 



The reason for particularly specifying the sulphate, is that 

 the sulphuric acid possesses many properties which approach to 

 those of the phosphoric acid, and may, therefore, in the interior 

 of the plant, perform chemical functions of a similar kind. 



The phosphate of ammonia is not here recommended for the 

 first time. It has already been tried, along with other sub- 

 stances, by Mr Lawes, on the turnip crop of 1844, as follows : 



No manure gave, of bulbs, ... 2 tons 4 cwt, 



Farm-yard manure, 12 tons, . . . 10 ... 15 ... 

 Superphosphate of lime, 4 cwt., . j 1 _ 



Phosphate of ammonia, 56 lb., . . J 



Superphosphate of lime, 4 cwt., . ) 



Sulphate of ammonia, 56 lb., . . 



Superphosphate of lime, 4 cwt., 

 Rape-cake, 4 cwt., .... 



As we have no experiment with the superphosphate applied 

 alone, the above results if we may rely upon crops of bulbs, 

 which are so very small merely indicate that the phosphate of 

 ammonia, under the circumstances, produced an effect about 

 equal to that of eight times its weight of rape-dust, and some- 

 thing greater than that of its own weight of sulphate of ammonia. 

 They urge as strongly, however, to further more comparative 

 and duplicate experiments with these several substances applied 

 alone. 



2. Ammoniacal phosphate of soda. This salt is formed by 

 dissolving together in hot water six or seven parts of the com- 

 mon phosphate of soda of the shops with one of sal-ammoniac, 

 and setting the solution aside to cool. It crystallises in large 

 transparent prisms, which possess a cooling saline taste, effloresce 

 slightly in the air with loss of ammonia, and dissolve readily in 

 water. They consist of 



Ammonia, . . . . . . 8.11 per cent. 



Soda, 14.89 



Phosphoric acid, . . . . 34.06 



Water, - . 42.94 ... 



100 

 The equivalent weight of this salt is 262. 



The presence, in this compound, of ammonia, soda, and 



* Journal of the Royal Agricultural Society, vol. viii. p. 510. 



