500. In so far as the _air_ has acted upon the Earthy during its origin, it has imparted to it electrical and combustible properties; the metal has combined with hydrogen, has become an Inflammable, as in sulphur or pit-coal. Sulphur may be regarded as the intimate fusion of hydrogen with metal; coal as a combination of the same probably elicited by means of oxygen. Inflammables are idioelectric and combustible, because they are rigidified air. That matter belongs only to the Inflammables, which, being once kindled in exposure to the air, continues to burn of _itself_. The Inflammables are volatile, since they undergo combustion, i. e. they take on the condition of their antetype, the air. They have from metal the opacity and the colours, but they do not preserve the lustre or self-illumination. They become transparent simply by crystallization or oxydation. 501. With the generation of the Earthy _water_ imparts also to a portion of the same its properties, dissolubility and transparency. To the metal and hydrogen oxygen is next added. An hydrated Earthy originates. The Aqueo-earthy is fluid in water; it is _salt_. Salt changes its form in the readiest manner, because it is the metatype or likeness of water; and hence its susceptibility to crystallization. It is not combustible by itself, because it is essentially an oxyde and hydroid. Salt is a metal or Inflammable that has undergone combustion, and can therefore never be simple. 502. Now that part of the earth-element, which remains after the salt, the Inflammable and the metal have been separated, is plainly the _Earthy_ or the _earth_. It has therefore no aqueous properties, is not soluble; it has no aerial properties, is not electric and combustible; has no metallic properties, is not heavy, nor opaque and glittering, not fusible and malleable or extensible. The pure Earthy is always fixed or firm, and therefore figurate. The Earthy is a metal, with which the oxygen has been intimately melted down; for it is the identification of all elements. 503. The Earthy is the principal mass, because it represents the earth-element itself. Salt, Inflammable and metal are only subordinate masses, because they are only displacements of the earth-element by the other elements. Therefore a small part only of the Earthy has become salt, a yet smaller Inflammable, and the smallest, metal. 504. Although the metal is simple, it can by no means correspond, as might otherwise appear, to the earth-element; for every element is a totality of elemental bodies, and therefore those minerals, which represent the pure earth-element, must be compound, without, however, exhibiting the characters of the other elements. This is found only in the earths. 505. There are, accordingly, in a genetic point of view, four, and only four, mineral classes. They originate in an ascending direction, from the earth-element by water and air up to fire. The Classes are--