quivocal proof of its materiality. A matter is thrown from heated bodies, which moves in right lines, with velocity, raises the temperature of any body, on which it falls; and which, in every state, preserves the properties of caloric." no proof of its But are these proofs of materiality? By no means. If materiality. every thing were material, of which these properties could be predicated, then should we have proofs of something substantial in sound and cold. Thus sound is thrown from surrounding bodies, in right lines, with velocity, is capable of reflection and of condensation, occasions sound in some bo→ dies on which it falls, and, in every state, preserves the properties of sound. Cold also moves in right lines, with velocity, suffers reflection and condensation, lowers the temperature of bodies, and is always and absolutely cold. Heat of the Sun distinct from light. This will be considered hereafter. "Lastly," it is said, that "the existence of caloric, in the rays of the sun, apart from visible light, adds to the proof, that a peculiar matter exists, possessed of the properties of caloric, and distinct from every other." It is sufficient to have mentioned this last alleged proof of the existence of material caloric; its validity rests entirely on the supposition, that no other explanation can be given of the phenomenon; and it will consequently fall to be considered, in the second division of our subject. (To be concluded in our next.) Muriates of XII. On some of the Combinations of Oximuriatic Gas and Oxigen, and on the Chemical Relations of these Principles to inflammable Bodies. By HUMPHRY DAVY, Esq. LL, D. Sec. R. S. Prof. Chem. R. I. F. R. S. E. (Concluded from p. 127.) 3. On the Combinations of the Metals of the Earths with Oxigen and Oximuriatic Gas. THE muriates of baryta, lime, and strontia, after being the earths not a long time in a white heat, are not decomposable by any simple attractions: thus, they are not altered by boracic decomposable acid, though, when water is added to them, they readily without water. afford muriatic acid and their peculiar earths. metals with oximuriat.c From this circumstance, I was induced to believe, that Compounds of these three compounds consist merely of the peculiar metallic bases, which I have named barium, strontium, and calcium, and oximuriatic gas; and such experiments as I have been able to make, confirm the conclusion. gas. evolve one Wheu baryta, strontia, or lime, is heated in oximuriatic The earths gas to redness, a body precisely the same as a dry muriate is part of oxigen formed, and oxigen is expelled from the earth. I have for two of oxi never been able to effect so complete a decomposition of muriatic gas. these earths by oximuriatic gas, as to ascertain the quantity of oxigen produced from a given quantity of earth. But in three experiments made with great care I found, that one of oxigen was evolved for every two in volume of oximuriatic gas absorbed. I have not yet tried the experiment of acting upon oxi- Direct union muriatic gas by the bases of the alkaline earths; but I have not yet tried. not the least doubt, that these bodies would combine directly with that substance, and form dry muriates. duced from In the last experiment that I made on the metallization Earths proof the earths by amalgamation, I paid particular attention their metallic to the state of the products formed by exposing the resi- bases, duum of amalgams to the air. I found, that baryta formed in this way was not fusible at an intense white heat, and that strontia and lime so formed gave off no water when ignited. Baryta made from crystals of the earth, as Mr. not hydrates Berthollet has shown, is a fusible hydrate; and I found, that this earth gave moisture when decomposed by oximuriatic gas; and the lime, in hydrate of lime, was much more rapidly decomposed by oximuriatic gas than quicklime, its oxigen being rapidly expelled with the water. as the com mon earths, heated in muriatic gas. Some dry quicklime was heated in a retort, filled with Dry quicklime muriatic acid gas: water was instantly formed in great abundance, and it can hardly be doubted, that this arose from the hidrogen of the acid combining with the oxigen of the lime. As potassium so readily decomposes common salt, I Action of potthought it might possibly decompose muriate of lime, and assium on the thus muriates of the earths. Combination of magnesia, alumine, and silex, with muriatic gas. Barytes ab. sorbs oxigen. Lime apparently not. Oximuriate. Oxigen produced from oximuriatic gas and mag nesia. thus afford easy means of procuring calcium. The rapidity with which muriate of lime absorbs water, and the difficulty of freeing it even by a white heat from the last portions, rendered the circumstances of the experiments unfavourable. I found, however, that by heating potassium strongly, in contact with the salt, in a retort of difficultly fusible glass, I obtained a dark coloured matter, diffused through a vitreous mass, which effervesced strongly with water. The potassinm had all disappeared, and the retort had received a heat at which potassium entirely volatilizes. I had similar results with muriate of strontia, and (though less distinct, more potassium distilling off unaltered) with muriate of baryta. Either the bases of the earths were wholly or partially deprived of oximuriatic gas in these processess, or the potassium had entered into triple combina tion with the muriates. I hope on a future occasion to be able to decide this point. Combinations of muriatic acid gas with magnesia, alumine, and silex, are all decomposed by heat, the acid being driven off, and the earth remaining free. I conjectured from this circumstance, that oximuriatic gas would not expel oxigen from these earths, and the suspicion was confirmed by experiments. I heated inagnesia*, alumine, and silex to redness in oximuriatic gas, but no change took place. Messrs. Gay-Lussac and Thenard have shown, that baryta is capable of absorbing oxigen; and it seems likely, (as, according to Mr. Chenevix's experiments, most of the earths are capable of becoming hyperoximuriates) that peroxides of their bases must exist. I endeavoured to combine lime with more oxigen, by heating it in hyperoximuriate of potash, but without success, at least after this process it gave off no oxigen in combining with water. The salt, called oximuriate of lime, made for the use of the bleachers, I found gave off oxigen by heat, and formed muriate of lime. From some experiments of Messrs Gay-Lussac and Thenard, Bul let. de la Societ. Phil. Mai, 1810, it appears, tha oxigen is rocured by passing oximuriatic gas over magnesia at a high temperature, and that a muriate indecomposable by heat is produced. They attribute the presence of this oxigen to the decomposition of the acid; but, according to all analogies, it must arise from the decomposition of the earth. From earthy muri From the proportions which I have given in the fast Component Bakerian lecture, but which were calculated from the ana parts of the lyses of sulphates, it follows, that, if the muriate of barytu, ates. strontia, and lime, be regarded as containing one proportion of oximuriatic gas, and one of metal, then they would con sist of 71 barium, 46 strontium, and 21 calcium, to 32.9 of oximuriatic gas. To determine how far these numbers are accurate, 50 grains of each of these muriates, that had been heated to whiteness, were decomposed by nitrate of silver, the precipitate was collected, washed, heated, and weighed.. The muriate of baryta, treated in this way, afforded 68 grains of horn-silver. The muriate of strontia 85 grains. The muriate of lime 125 grains. From experiments to be detailed in the next section, it Horn silver. appears, that horn-silver consists of 12 of silver to 3'9 of oximuriatic gas, and consequently, that barium should be represented by 651, strontium by 46-1, and calcium by 20.8. 4. On the Combinations of the Common Metals with Oxigen and Oximuriatic Gas. In the limits which it is usual to adopt in this lecture, it Combinatione will not be possible for me to give more than an outline of of oximuriatic gas with me the numerous experiments, that I have made on the combi- tals. nations of oximuriatic gas with metals; I must confine myself to a general statement of the mode of operating, and the results. I used in all cases small retorts of green glass, containing from 3 to 6 cubical inches, furnished with stopcocks. The metallic substances were introduced, the retort exhausted and filled with the gas to be acted upon, heat was applied by means of a spirit lamp, and after cooling, the results were examined, and the residual gas analysed. in it. All the metals that I tried, except silver, lead, nickel, Metals heated cobalt, and gold, when heated, burnt in the oximuriatic gas, and the volatile metals with flame. Arsenic, anti * If Mr. James Thompson's analysis of sulphate of barytes be made the basis of calculation, sulphuric acid being estimated as 36, then the number representing barium will be about 65.5. VOL. XXIX.-JULY, 1811. mony, Product from arsenic, antimony, tellurium, mercury, zinc, iron, copper, manganese, Resin of cop per. mony, tellurium, and zinc with a white flame, mercury with a red flame. Tin became ignited to whiteness, and iron and copper to redness; tungsten and manganese to dull redness; platina was scarcely acted upon at the heat of fu sion of the glass. The product from arsenic was butter of arsenic; a dense, limpid, highly volatile fluid, a nonconductor of electricity, and of high specific gravity, and which, when decomposed by water, gave oxide of arsenic and muriatic acid. That from antimony was butter of antimony, an easily fusible and volatile solid, of the colour of horn-silver, of great density, crystallizing on cooling in hexaedral plates, and give ing, by its decomposition by water, white oxide. The product from tellurium, in its sensible qualities, resembled that from antimony, and gave when acted on by water white oxide. The product from mercury was corrosive sublimate. That from zinc was similar in colour to that from antimony, but was much less volatile. The combination of oximuriatic gas and iron was of bright brown; but having a lustre approaching to the metallic, and was iridescent like the Elba iron ore. It volati lized at a moderate heat, filling the vessel with beautiful minute crystals of extraordinary splendour, and collecting in brilliant plates, the form of which I could not determine. When acted on by water, it gave red muriate of iron. ⚫ Copper formed a bright red brown substance, fusible at a cheat below redness, and becoming crystalline and semitransparent on cooling, and which gave a green fluid, and a green precipitate by the action of water. • The substance from manganese was not volatile at a dull fed heat; it was of a deep brown colour, and by the action of water became of a brighter brown: a muriate of manga It is worth inquiry, whether the precipitate from oximuriate of cop. per by water is not a hydrated submuriate, analogous in its composition to the crystallized muriate of Peru. This last I find affords muriatic acid and water by heat, The resin of copper discovered by Boyle, formed by heating copper with corrosive sublimate, probably contains only 1 proportion of oximu-, riavic gas, while that above referred to must contain 2, pese, |