that both hydrogen and nitrogen are oxides ; but from the action of potassium on ammonia, it would rather appear that nitrogen alone is in that instance decomposed.
But there is great difficulty in reasoning upon the precise nature of this amalgam, on account of the presence of water, which it is at least extremely difiicult to avoid, as the amalgam cannot be formed in dry ammoniacal gas, nor by means of any dry compound of ammonia yet tried.
The driest amalgam is that formed by an alloy in which potassium is also present. In endeavouring to distil ammonium from this compound, there is always a partial regeneration of ammonia mixed with about one third hydrogen; and if the proportion of oxygen contained in ammonia be inferred from this product, it would appear to be forty-eight per cent.,—a resultswhich agrees with the quantity which might be presumed to exist in ammonia, from the proportion in which it unites with acids. But if the proportion of hydrogen to ammonia thus evolved be less than that of one to two, the results will not accord; and then, says Mr. Davy, it may reasonably be supposed that hydrogen and nitrogen are both oxides, either of the same metal or of different metallic bases. But if, instead of endeavouring to accommodate our general antiphlogistic notions to the peculiar facts respecting ammonia, we endeavour to frame a phlogistic hypothesis to account for them, we must then suppose nitrogen to be a simple basis, which becomes alkaline with one dose of hydrogen; and metallic, by uniting with some greater proportion of the same element.
The author next details avariety of experiments, made on several of the earths, for the purpose of decomposing them. The metals of silica, alumina, and glucine, were obtained in alloy with iron; but it appeared that these metals could not be made either in direct combination with mercury, or as a triple alloy with mercury and potassium. By passing potassium, however, through the alkaline earths, lime and magnesia, and afterwards introducing mercury, solid triple amalgams were obtained. The triple amalgam from magnesia was easily deprived of its potassium by means of water; and it then appeared as a solid white metallic mass, which by long exposure to air was covered with a crust of magnesia. This section concludes with speculations on the probable quantity of oxygen contained in the earths, founded on Mr. Dalton's law of chemical union by simple particles, which appears to Mr. Davy more near the truth than that modification of it lately observed by M. Gay-Lussac.
The concluding section of the lecture contains some theoretic considerations on the nature of hydrogen in particular, and on the whole class of simple substances in general.
The fact of hydrogen uniting with tellurium and with sulphur into compounds apparently acid, it is observed, militate strongly against its being simple; and Mr. Davy inclines to consider it an oxide, of which the base exists in the amalgam of ammonium. Ammonia will then be the deutoxide of the same base, and nitrogen the tritoxide.
The class of pure infiammables will on this antiphlogistic hypo-
