346 Dr. Henry on the Analysis of some of [Nov. 



by boiling water, the carbonate was dissolved out of the excess 

 of charcoal by muriatic acid ; the solution decomposed by sul- 

 phate of soda; and, from the quantity of sulphate of baryta, 

 its equivalent in carbonate, and the quantity of carbonic acid in 

 the latter compound, were determined. 



The analyses of the mixture of gases was made with the 

 greatest care, and was thrice repeated. Reckoning up the 

 oxygen contained in all the different products, and the nitrogen 

 both free and in the nitrous gas, the volume of the latter was 

 found to be to that of the former as 7-9 to 19-85, or as 1 to 2-51 ; 

 thereby fully confirming that view of the proportion of the ele- 

 ments of nitric acid, which had previously been derived from 

 synthetic experiments. 



If then nitrous oxide be taken as the binary combination, in 

 which the elements, nitrogen and oxygen, exist atom to atom 

 singly, two volumes of nitrogen will contain the same number 

 of ultimate particles or atoms as one volume of oxygen. And 

 imagining the smallest possible volume of each of those gases, 

 or a volume containing only a single atom, the ultimate volume 

 of nitrogen will be double the ultimate volume of oxygen. Two 

 measurable volumes of nitrogen, when chemically united with 

 one of oxygen, or with two, three, or more volumes, will afford 

 compounds of nitrogen and oxygen, in which the atoms will 

 bear the proportion of one to one, or one to two, to three, or 

 to more atoms. And as two volumes of nitrogen are, in nitric 

 acid, combined with five of oxygen, that acid is justly consi- 

 dered as constituted of one atom of nitrogen, the relative 

 weight of which is 14, and five atoms of oxygen weighing to- 

 gether 40. 



3. — Analysis of Ammonia. 



Another combination of nitrogen, the exact analysis of which 

 is of great importance, from the connection of the results with 

 the law of volumes, as well as with the atomic system, is that 

 into which it enters with hydrogen. Only one compound of 

 those two elements, viz. ammonia, has yet been discovered, 

 the decomposition of which, when existing as a permanent gas 

 over mercury, may, as is well known, be effected by subjecting 

 it to a long continued succession of electrical sparks, or of dis- 

 charges from a Leyden jar. This method, originally discovered 

 by Dr. Priestley, has been employed by the late Count Ber- 

 thollet, by Sir H. Davy, by Mr. Dalton, and by myself, with a 

 view to the accurate analysis of the gas. The process, how- 

 ever, being one into which sources of error may easily be in- 

 troduced, there is not so perfect an agreement, as might have 

 been wished, among the results of different observers. Without 

 entering into a detail of these discrepancies, or a statement of 

 their causes, it may be sufficient to observe that the view of 



