509. The _Inflammables_ divide under a chemical point of view into two groups--into the varieties of Coal and Sulphur, whereof the Earthy lies at the basis of the former which is non-fusible; the Aerial at that of the latter. They do not admit of being divided, unless a mean betwixt the two be taken, the combinations of carbon and hydrogen in the resins. 510. The _Salts_ admit of a better dismemberment. Their constituent parts are alkalies and acids, the former the Earthy, the latter the Aqueous. The mean condition is exhibited by the neutral salts, so that three orders are the result. 511. Now by the philosophical view we have first attained to the very remarkable import of the acids. They are forsooth nothing else than oxydized elements and mineral classes. In the nitric acid it is evident that, as the acid of nitrogen, it is the _aerial acid_; as sulphuric acid is the _inflammable acid_; arsenic acid the _metallic acid_. Upon this ground we may expect that the other acids also have a similar origin. Without much hesitation hydrochloric acid may be viewed as the _aqueous acid_, which is associated with the sea; the carbonic acid as _æther-_ or _igneous-acid_, as well on account of its constituent parts and gaseous character, as chiefly on account of its general diffusion. There remain then only two that have been called mineral acids, the fluoric and boracic acids, the first of which, as conqueress of the earths is the _earth acid_, the last being thus the acid of the _salts_. We have accordingly-- a. _Elemental acids._ 1. The oxydized æther is Carbonic acid. 2. The oxydized air Nitric acid. 3. The oxydized water Hydrochloric acid. b. _Mineral acids._ 4. The oxydized earth is Fluoric acid. 5. The oxydized salt Boracic acid. 6. The oxydized inflammable Sulphuric acid. 7. The oxydized metal Arsenic acid. 512. The vegetable and animal acids are none other than repetitions of the elemental and mineral acids. They may perhaps be parallelized in the following manner. Fire-acid (Carbonic acid) Acetic acid Hæmatosine. Air-acid (Nitric acid) Malic acid Lactic acid. Water-acid (Hydrochloric acid) Saccharine acid Mucic acid. Earth-acid (Fluoric acid) Tartaric acid Phosphoric ac. Salt-acid (Boracic acid) Tannic acid Uric acid. Inflammable-acid (Sulphuric acid) Succinic acid Sebacic acid. Ore-acid (Arsenic acid) Indic acid Formic acid. All the remaining acids must be viewed as subordinate to, or as kinds of these. 513. The _alkalies_ appear to follow the same course, though it does not admit of being so completely demonstrated.