of the presence of oxygen in that acid: but Mr. Davy observes, that an opposite doctrine may be equally maintained; since the metals may consist of bases united with hydrogen, which, by combining with oxymuriatic acid, converts it into muriatic acid. A corresponding doubt occurs also respecting the nature of hypercxygenized muriatic acid. Does the oxymuriatic acid combine with oxygen as well as with hydrogen? and does it, with the former, produce hyperoxygenized muriatic acid? or is the hyperoxygenized acid the base of this class? and does this unite with difment proportions of hydrogen? In order to answer these questions, Mr. Davy has endeavoured to obtain the neutralizing acid in hyperoxygenized muriatc of potash. by distillation with dry boracic acid; but in this case, oxygen is the chief gaseous product, and there remains common muriate of potash, not decomposable by any dry process. Other attempts were also made to solve the same problem, by attending to the phenomena which occur in the decomposition of various compounds by the agency of voltaic electricity. The fact most favourable to the existence of hydrogen in oxymuriatic acid takes place during the electrization of oxymuriate of tin. Hydrogen, which in this case is extricated, must be produced either by the metal or by the oxymuriatic acid.
No substance, says Mr. Davy, has less claims to be considered an acid than oxymuriatic acid; and he considers it a body sui generis, that has a tendency to combine with pure inflammablc matters, forming what are called the dry muriates. Of this class are the common metallic muriates, the muriates of potash, of soda, lime, strontites, and barytes. But there are other bases which in their state of oxide unite with muriatic acid gas, and retain the water which is formed in their composition. Such are, the muriates of ammonia, of magnesia, of zircon, alumina, and yttria.
Although the modern chemical nomenclature accords extremely ill with these views of the composition of the several forms of muriatic acid, and of muriatic salts, the author does not venture to propose any alterations in their names until their real nature shall be more fully known.
Among the various compounds of oxymuriatic acid with combustible substances, there is one which the author has examined with peculiar care, and with very singular results. He has on a former occasion examined the action of oxymuriatic acid upon phosphorus, and has described two compounds, the one fluid, the other solid; the first of which, according to the generally-receivcd theory, should consist of muriatic acid and phosphorous acid; and the second of muriatic acid and phosphoric acid. If such were really the- case, be imagined it would not be difficult to obtain the phosphoric acid as proof of the presence of oxygen; and he accordingly saturated the compound with pure ammoniacal gas, expecting to obtain muriate of ammonia, and phosphate of ammonia, which, by being heated, would leave the phosphoric acid in a pure state.
The triple compound formed was, on the contrary, a dry powder, not fusible by a red heat, nor yielding any gaseous matter when
