After the enumeration of these Important subjects, we cannot de better than refer to them in the words of his brother and biographer "I shall not," says Dr. Davy, "attempt an analysis of these papers; I shall give merely a sketch of the most Important facts and disco.
writes which they contain, referring the chemical reader to the original for full satisfaction. After the extraction of metallic bases from the fixed alkalies, analogies of the strongest kind indicated that the rake live earths are similarly constituted ; and ho succeeded in proving this In a satisfactory manner. But owing to various circumstances 01 peculiar properties, be was not able on his first attempts to obtain the metals of those earths In a tolerably pure and insulated state for the purpoeo of examination, On his return to the laboratory elle] his illness, this was one of his first undertakings. lie accomplished 11 to a certain extent by uniting a process of DIM. Berzelius and I'outin who were then engaged in the same Inquiry, with one of his own. 133 negatively electrifying the earths, slightly and mixed wit! red oxide of mercury, In contact with a globule of mercury, le obtained amalgams of their metallic bases ; and by distillation, witl peculiar precautions, he expelled the greater art of the mercury Even now, in consequence of the very minute quantities of the basic hich Imo procured, and their very powerful attraction for oxyjeu, hi vas only able to ascertain a few of their properties in a hasty manner. ['hey were of silvery lustre, solid at ordinary temperatures, fixed at a eel heat, and heavier than water. At a high temperature they hatracted oxygen from the glass, and at ordinary temperatures from he atmosphere and water, the latter of which in consequence they lecomposed.
"The names ho proposed for them, and by which they have since >can called, were barium, strontium, calcium, and snagnium, which us afterwards altered to magnesium.
"The came analogies were nearly as strong applied to tho proper earths; and he attempted their decomposition in a similar manner, ant not with the same success. By the action of potassium proof was >btained that they consist of bases united to oxygen ; but whether bases were inflammable substances merely, or metallic) inflam mable substances, was yet a problem, which has since been solved by he labours of Willer, Bussy, and Berzelius. Analogy was in favour
if the latter inference, as was also the circumstance that the bases of these earths are capable of entering Into union with iron ; and this has been confirmed by the inquiries just mentioned as regards the majority of them, all but the basis of silica, which yet remains doubtful.
"The application of these facts to geology was full of promise; and be indulged in the hope that they might serve to explain not ouly some of the moat mysterious phenomena of nature, as earthquakes amid volcanoes, and the combustion of meteoric stones and falling stars, but might ultimately lead to a general hypothesis of the forma tion of the crust of the earth." His Ideas on this last subject, which he afterwards in great measure relinquished, may be seen in Dr. Davy's Life of Sir liumphry,' p. 397.
After effecting the decomposition of the fixed alkalis, Davy, reasoning from analogy, conjectured that ammonia might also contain oxygen, and his first experiments were favourable to this supposition; but they contained a fallacy. In his various papers on ozymuriatic acid and its compounds; ho establishes the views of Scheele respecting its nature, and proves that the reasoning of Berthollet, which had generally been admitted by chemists, was fallacious. He shows that oxymuriatic acid is not a compound, as supposed, of =Antic acid and oxygen, but an undecomposod body, to which, ou account of its green colour, he gave the name of chlorine. In 1810 ho published the first volume of his ' Elements of Chemical Philosophy,' which, although they bear marks of haste, contain much interesting matter: uo further portion of this work was printed. His 'Elements of Agricultural Chemistry,' which appeared soon after, is a work containing much useful matter, and replete with sound and practical views of the subject.
One of his greatest inventions was that of the miner's safety.lamp, the first paper in relation to which appeared in the ' Philosophical Transactions' for 1815, and the last iu 1817.