Part 32

Bones and teeth are ſometimes found replete with the blue calx of copper. Bits of copper pyrites often ſtick in petrefactions, but ſeldom conſtitute their whole ſubſtance. I have some such from Norway, in a matrix of magnetical iron ore.

Iron with an organic Form.

§ 277.

Calciform iron ſometimes is found in the ſhape of roots and branches of trees. When mineralized by ſulphur, it frequently exiſts in petrefactions, but ſeldom conſtitutes the whole maſs.

Zinc with an organic Form.

§ 278.

I have ſeen pſeudo-galena (black jack), in the form of coral.

§ 279.

Some modern writers, as well as Mr. CRONSTEDT, place the productions of volcanoes in an appendix by themſelves; but, I think, to no good purpoſe. Things formed by the hand of nature, whether by a liquid or a dry proceſs, muſt not be diſjoined; for ſhe frequently avails herſelf of both methods in one and the ſame inſtance. And, indeed, the origin of many things is ſo very doubtful, every veſtige thereof being obliterated, that even an Œdipus could not with certainty determine how they were produced. And, on the other hand, many aſſert, that almoſt the whole of the mineral kingdom is the product of fire. To avoid error, therefore, it is better to claſs foſſil ſubſtances according to their conſtituent parts, which proper experiments will lay open to us; for we can seldom know their origin or formation.

Homogeneous ſubſtances joined together, but not primitive, will find a place among the ſtones, or elſewhere, in the firſt appendix.

FINIS.

INDEX.

N. B. The Numbers refer to the Sections.

Acids, how known § 25

Aerial acid 37

Alkali minerale aeratum 55

—— —— nitratum 48

—— —— ſalitum 49, 76

—— —— vitriolatum 47

—— vegetabile aeratum 54

—— —— nitratum 45

—— —— ſalitum 46

—— —— vitriolatum 44

—— volatile aeratum 56

—— —— nitratum 51

—— —— ſalitum 52

—— —— vitriolatum 50

Alkalies, how known 38