1813.] Azote, of Hydrogen, and of Ammonia. 283 



dried. With this solution I mixed concentrated muriatic acid, 

 and then added 9-V parts of copper. The solution of the copper 

 was promoted by the application of heat, and at the end of six 

 hours it was all dissolved. The liquor had assumed a brownish 

 blue colour, holding in solution a little of the muriate of copper 

 [murias cuprosus). The evolution of nitrous gas continued still 

 four hours longer, and the liquid gradually assumed a green 

 colour. After sixteen hours the apparatus was allowed to cool. 

 When the greenish liquid was mixed with distilled water it 

 became milky, in consequence of the precipitation of the murias 

 mfnwust but the precipitate subsided very slowly, and was for 

 the most part (as usually happens) converted into murias cupri- 

 cus before it could be collected, dried, and weighed. To judge 

 from appearances, its weight could not have amounted to one 

 part. Its presence, however, shows that the nitric acid was 

 entirely decomposed. The nitrous gas, examined by means of 

 muriate of iron, left so small a quantity of unabsorbed residue, 

 that we can only ascribe it to the azotic gas disengaged from 

 the water in the pneumatic apparatus. 



Let us examine the result of this experiment: 12'05 parts of 

 nitrate of barytes contain 5 '00 parts of pure nitric acid, which 

 (supposing the determination of Davy and Dalton accurate) is 

 composed of 2207 oxygen and 2'793 of nitrous gas: but if the 

 determination of Gay-Lussac be the most correct, the five parts 

 of acid are composed of 1*738 of oxygen and 3*262 of nitrous 

 gas. According to the first supposition the 5'00 of acid will 

 be capable of pcroxidizing 9*12 parts of copper, while accord- 

 ing to the second they will only peroxidize 7'00 parts of that 

 metal: but in the experiment above described 9*5 parts of cop- 

 per had been dissolved, while at the same time a small quantity 

 of muriate of copper had formed, owing to the surplus of 

 copper dissolved. We cannot attribute the difference between 

 7 and i)\ to the formation of muriate of copper, because in that 

 case the quantity of muriate deposited would have amounted 

 to "!\ part>, which is much greater than the truth. 



Experiments prove, then: — 



1. That azote cannot be considered as the radicle of nitric 

 acid; but that the acid must contain another radicle, the weight 

 of which must be 11*72 per cent, of the acid. 



2. That nitric acid docs not contain more than 26*43 of 

 azote to 73 57 of oxygen, nearly the numbers established by 

 Dairy in his Elements of Chemical Philosophy, 



3. That the acid containing only 1 1 • 7 2 per cent, of radicle, 

 but '..'<;:; per cent, of azote, it follows that li*7'2 of radicle 

 united to ii-7i of oxygen constitutes azote. Hence azote is 

 touiposed as follows: — 



