262 PHILOSOPHICAL TRANSACTIONS. [ANNO 1798. 



Nitric acid was poured, as before, into the retort, for the 3d time, but very 

 little gaz ascended, and much less white fumes than before. The distillation pro- 

 ceeded, till about 1 dr. measure of liquid remained in the retort: this being left to 

 stand, prismatic crystals were formed in a very small quantity of liquid. These 

 crystals did not taste sour, but sharp, and they reddened turnsole-paper. Adding 

 a little soda to a part of them, to see whether I could form a neutral salt, I was 

 surprized by the extrication of ammonia. To another portion of crystals, I 

 added sulphuric acid, which disengaged nitric acid. A 3d portion of crystals, being 

 exposed over a lamp, wholly evaporated, without leaving a mark behind. The 

 remaining matter in the retort being examined, was found to be nitrate of ammo- 

 nia. It was plain that the nitric acid had, by parting with oxygen to the carbon 

 of the oxide, formed carbonic acid. The carbon being thus carried off, of course 

 the nitrogen and hydrogen of the oxide uniting produce ammonia, which, uniting 

 with the redundant nitric acid, composes nitrate of ammonia; but great part of 

 the nitrate of ammonia was carried off in the vapour state, exhibiting white 

 fumes, and sublimate, as above observed. The mode of making the experiments 

 with the other acids was of course different from the former experiment. 



Exper. 2. Twenty-five grains of the above animal oxide, and \ oz. of water, were 

 put into a bottle capable of containing 3 pints; a stream of oxymuriatic acid gaz, 

 from manganese and muriatic acid, was made to pass into the bottle, and on the 

 charge, for 12 hours; and, for 24 hours more, oxymuriatic gaz kept issuing, but 

 in smaller quantity, and circulating through the bottle. The oxide, by this time, 

 was completely dissolved. On adding lime to a little of the solution of it, ammo- 

 nia was disengaged ; and, on adding sulphuric acid, there was a disengagement of 

 oxymuriatic acid. On evaporation however I obtained nothing but muriate of 

 ammonia, with which was mixed a little manganese. In this experiment, I could 

 not doubt that the carbon had been carried off, in the state of carbonic acid, by 

 the oxygen of the oxymuriatic acid; and thus ammonia was compounded, from the 

 union of the 2 remaining constituent parts of the oxide, viz. the nitrogen and 

 hydrogen. The oxymuriatic acid, united to the ammonia, parted with oxygen, 

 and became muriatic acid during evaporation; hence, muriate of ammonia was 

 formed. 



Exper. 3. The above experiment was repeated, only the gaz was nitro-muriatic 

 gaz, from a mixture of nitric and muriatic acids. The result was the same as in 

 the last experiment, except that the product was a mixture of nitrate and muriate 

 of ammonia. 



I made other experiments of the same kind, but their results were so nearly the 

 same as those above related, that I shall not give an account of them. By the 

 unexpected issue of these experiments, all my hopes of acidifying the animal oxide 

 were exploded; but I am indebted to that pursuit, for the curious discovery of the 

 change of the most common basis of urinary concretions, the animal oxide, into 

 ammonia and carbonic acid, by the oxygen of the above acids; which will be 



