PHOSPHATE, AND NITRATE OF AMMONIA. 187 



This salt is also without smell, and is of constant composition. 

 It deliquesces slowly when exposed to moist air. 



( Phosphoric acid, 53.9 



4. Phosphate of ammonia consists of < Ammonia, 25.7 



( Water, . 20.4 



100 



This salt effloresces slightly in the air, and loses a part of its 

 ammonia. It is much more stable, however, than the carbonate. 

 It exists in the urine of man, and in that of carnivorous animals. 

 It is prepared in the same way as the phosphate of soda, 

 by treating an excess of burned bones with sulphuric acid, de- 

 canting the liquid, saturating it completely with carbonate of 

 ammonia, and setting it aside to crystallise. 



{Nitric acid, . 67.5 

 Ammonia, . 21.2 

 Water, . 11.3 



100 



This salt deliquesces readily in moist air, and slowly loses a 

 small portion of its ammonia. 



6. Acetate of ammonia is prepared by saturating common 

 vinegar with carbonate of ammonia, and evaporating by a 

 gentle heat. It may be more cheaply made by mixing crude 

 wood vinegar (pyroligneous acid) with the ammoniacal liquor 

 of the gas-works. The composition of this salt has not been 

 accurately determined. I notice it here chiefly in consequence 

 of the statement of Persoz, (see page 95,) that a very small 

 quantity of it applied to certain plants produces a decidedly in- 

 jurious effect, a statement which is deserving of careful expe- 

 rimental examination. 



f Oxalic acid, 58.1 



7. Oxalate of ammonia consists of < Ammonia, . 27.4 



( Water, . 14.5 



100 



This salt crystallises in beautiful small prisms, and is soluble 

 in 28 parts of cold water. It is much used in the laboratory, 



