294 Dr. Murray on the Chemical Constitution of Acids, !<c. [Oct. 



the common hypothesis. Dr. Wollaston has observed, that to 

 decompose nitrate of potash so as to afford nitric acid, it is 

 necessary lo employ as much sulphuric acid as forms bisulphate 

 of potash ; and hence each portion of potash from which dry 

 nitric acid is separated will displace the water from two equiva- 

 lents of sulphuric acid. One of these portions of water, it may 

 be presumed then, will go as essential to the constitution of the 

 nitric acid, or rather its oxygen and hydrogen will do so, the 

 other is adventitious, though from the volatility and facility of 

 decomposition of the acid it may not be easily abstracted. 



On this view, the composition of the acid will be found to be 

 100 of nitrogen, 34 of oxygen, and 0*76 of hydrogen, which gives 

 6 as the multiple of oxvgen to the first proportion of that element. 

 The proportion of hydrogen is to the nitrogen as the first or 

 lowest equivalent, that in ammonia being the third, the former 

 being - 76 to 10, the latter to the same quantity of nitrogen 2*3. 



The same view of the composition of hydronitric acid may be 

 inferred from the proportion of oxygen and nitrogen in the dry 

 nitrates. In these, as in other analogous cases, the abstraction 

 of oxygen in the formation of water at their formation is compen- 

 sated by the oxygen of the base ; the metallic radical of the 

 latter merely i-eplaces the hydrogen of the acid, and the propor- 

 tion of oxygen to the radical of the acid remains the same. 



It thus appears, that the series of the nitrous compounds is 

 nitrous oxide, nitric oxide, nitrous acid, and nitric acid. The 

 oxygen in the first is to the nitrogen as 5*7 to 10; and taking 

 this first proportion of oxygen as 1, that in nitric oxide is 2, in 

 nitrous acid 4, and in hydronitric acid 6 — a ratio sufficiently 

 conformable to the law of definite proportions. 



If it were admitted that the oxygen and nitrogen remaining 

 after the action of hydronitric acid, and anhydrous nitrous acid, 

 formed binary compounds, which entered into direct combina- 

 tion with the alkali ; then from the abstraction of one proportion 

 of oxygen in the one by the formation of water, and in the other 

 by the production of nitric acid, compounds would be formed, 

 intermediate in the former between hydronitric and nitrous acid, 

 and in the latter between nitrous acid and nitric oxide, and thus 

 the series of the proportions of oxygen of 1, 2, 3, 4, 5, 6, would 

 be completed. This view, however, is not probable. At the 

 same time, the relation of these elements in these intermediate 

 proportions may exist in other ternary compounds, though they 

 are not found in binaiy combination, or in the ternary combina- 

 ions which they form with hydrogen, or with metallic bases. 



(To be continued.) 



