537. It is here shown, that freedom finds a place also in dead nature. Quartz only is necessary as the earth in general. Its marriages with the other earths, &c., to form precious stones are not necessary, but free or accidental, and may therefore happen for the first time in the laboratory. 538. If we now proceed to the arrangement of the Clay, we find exactly the same law to prevail in the genesis of its minerals i. e. stöchiometric combinations with other orders, classes, and elements. We have likewise-- A.--_Earth-Clays._ Fam. 1. Silicious clays Felspar. 2. Argillaceous clays Sapphire. 3. Talcose clays Ruby. 4. Calcareous clays Epidote. B.--_Class-Clays._ 5. Salt-clays Schorl. 6. Inflammable clays Azurite. 7. Ore-clays Harmotome. C.--_Elemental-Clays._ 8. Water-clays Clay-slate. 9. Air-clays Potter's-clay, Clay-stone. 10. Fire-clays Lavas, Phonolite, Toad-stone. The water-clays are hydrates; the air-clays volatilized hydrates; the fire-clays are clay fused or transmuted by heat. Here also the first 7 families only are crystallized; the 3 last, on the contrary, as well as the first in part, occur only in a compact state and in large masses. 539. The Talcs follow the same laws, and we have-- A.--_Earth-Talcs._ Fam. 1. Silicious talcs Mica. 2. Argillaceous talcs Sapphirine. 3. Talcose talcs Talc, Chlorite. 4. Calcareous talcs Augite. B.--_Class-Talcs._ 5. Salt-talcs Hornblende. 6. Inflammable-talcs Asbestus. 7. Ore-talcs Olivine. C.--_Elemental-Talcs._ Fam. 8. Water-talcs Serpentin, Steatite. 9. Air-talcs Lithomarge, Fuller's-earth, Bole. 10. Fire-talcs Basalt. 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._