Here also the first 7 families only are crystallized and occur for the most part in a scattered manner; but the aqueous, aerial, and igneous families, as well as the first family in part, are merely compact and mountainous masses.
540. The fourth order or that of the Calcareous earths is developed likewise according to the same laws. As, however, it approximates the salts, and therefore combines with acids, it presents many anomalous varieties, of which account cannot be taken in every instance. These minerals are soft throughout, change by fire and admit of being wholly or partially dissolved in acids. Here belong the zeolites, or combinations of the calcareous earths with the other earths.
| A.—Calcareous earths, Zeolites. | ||
|---|---|---|
| 1. | Silicio-calcareous earths | Lapis lasuli, Scapolite. |
| 2. | Argillaceo- " | Mesotype, Analcime, Stilbite. |
| 3. | Talco- " | Stellite. |
| 4. | Calcareo- " | Tabular spar. |
| B.—Classes of Calcareous earths. | ||
| 5. | Halo-calcareous earths | Boracite. |
| 6. | Inflammable- " | Phosphate of lime, Fluorspar? |
| 7. | Ore- " | Titanite, Tungsten. |
| C.—Elemental-Calcareous earths. | ||
| 8. | Water calcareous earth | Hydrophyllite? Wavellite. |
| 9. | Air- " | Gypsum, Heavy-spar, Celestine. |
| 10. | Fire- " | Limestone. |
Here also the first 7 tribes only occur crystallized, the 3 last, in a great measure, compact, and as mountainous masses.
CLASS II.
WATER-EARTHS. SALTS.
541. The chief distinctions of the salts consist also in their combination with the other classes, and we have therefore 4 orders—
| 1. Earth-Salts | Double-salts. |
| 2. Saline-Salts | Neutral-salts. |
| 3. Inflammable-Salts | Saponaceous-compounds. |
| 4. Metallic-Salts | Vitriols. |
The same will hold good without doubt of the orders, as in the case of the earths. They form as many families as there are principal masses of them present, with which they may combine. As the acids, from being the children or offspring of water, play the chief part in the water minerals, and are themselves nothing else than oxydized and outwardly lying masses, they carry consequently within themselves the number and import of the families; thus it is they which determine indeed the division. If the bases were to be taken as the groundwork of arrangement, there would be only earths and alkalies, and on the other hand numerous metals, by which step the mineralogist would fall into the unprincipled method of classification adopted by empirics. Here also the philosophy of nature shows, and that indeed upon sound reasoning, that the acids and not the bases afford the principle of a natural classification. A somewhat different opinion is held by the chemist, who must characterize the salts according to both series; but this is by no means the course taken by the historian of nature.