Such mixed systems of classification, resting partly on chemical and partly on physical characters, naturally appeared as the earliest attempts in this way, before the two members of the subject had been clearly separated in men’s minds; and these systems, therefore, we must first give an account of.
Sect. 2.—Mixed Systems of Classification.
Early Systems.—The first attempts at classifying minerals went upon the ground of those differences of general aspect which had been [341] recognized in the formation of common language; as earths, stones, metals. But such arrangements were manifestly vague and confused; and when chemistry had advanced to power and honor, her aid was naturally called in to introduce a better order. “Hiarne and Bromell were, as far as I know,” says[40] Cronstedt, “the first who founded any mineral system upon chemical principles; to them we owe the three known divisions of the most simple mineral bodies; viz., the calcarei, vitrescentes, and apyri.” But Cronstedt’s own Essay towards a System of Mineralogy, published in Swedish in 1758, had perhaps more influence than any other, upon succeeding systems. In this, the distinction of earths and stones, and also of vitrescent and non-vitrescent earths (apyri), is rejected. The earths are classed as calcareous, siliceous, argillaceous, and the like. Again, calcareous earth is pure (calc spar), or united with acid of vitriol (gypsum), or united with the muriatic add (sal ammoniac), and the like. It is easy to see that this is the method, which, in its general principle, has been continued to our own time. In such methods, it is supposed that we can recognize the substance by its general appearance, and on this assumption, its place in the system conveys to us chemical knowledge concerning it.
[40] Mineralogy, Pref. p. viii.
But as the other branches of Natural History, and especially Botany, assumed a systematic form, many mineralogists became dissatisfied with this casual and superficial mode of taking account of external characters; they became convinced, that in Mineralogy as in other sciences, classification must have its system and its rules. The views which Werner ascribes to his teacher, Pabst van Ohain,[41] show the rise of those opinions which led through Werner to Mohs: “He was of opinion that a natural mineral system must be constructed by chemical determinations, and external characters at the same time (methodus mixta); but that along with this, mineralogists ought also to construct and employ what he called an artificial system, which might serve us as a guide (loco indicis) how to introduce newly-discovered fossils into the system, and how to find easily and quickly those already known and introduced.” Such an artificial system, containing not the grounds of classification, but marks for recognition, was afterwards attempted by Mohs, and termed by him the Characteristic of his system.
[41] Frisch. Werner’s Leben, p. 15.
Werner’s System.—But, in the mean time, Werner’s classification had an extensive reign, and this was still a mixed system. Werner himself, indeed, never published a system of mineralogy. “We might [342] almost imagine,” Cuvier says,[42] “that when he had produced his nomenclature of external characters, he was affrighted with his own creation; and that the reason of his writing so little after his first essay, was to avoid the shackles which he had imposed upon others.” His system was, indeed, made known both in and out of Germany, by his pupils; but in consequence of Werner’s unwillingness to give it on his own authority, it assumed, in its published forms, the appearance of an extorted secret imperfectly told. A Notice of the Mineralogical Cabinet of Mine-Director Pabst von Ohain, was, in 1792, published by Karsten and Hoffman, under Werner’s direction; and conveyed by example, his views of mineralogical arrangement; and[43] in 1816 his Doctrine of Classification was surreptitiously copied from his manuscript, and published in a German Journal, termed The Hesperus. But it was only in 1817, after his death, that there appeared Werner’s Last Mineral System, edited from his papers by Breithaupt and Köhler: and by this time, as we shall soon see, other systems were coming forwards on the stage.
[42] Cuv. El. ii. 314.
[43] Frisch. p. 52.
A very slight notice of Werner’s arrangement will suffice to show that it was, as we have termed it, a Mixed System. He makes four great Classes of fossils, Earthy, Saline, Combustible, Metallic: the earthy fossils are in eight Genera—Diamond, Zircon, Silica, Alumina, Talc, Lime, Baryta, Hallites. It is clear that these genera are in the main chemical, for chemistry alone can definitely distinguish the different Earths which characterize them. Yet the Wernerian arrangement supposed the distinctions to be practically made by reference to those external characters which the teacher himself could employ with such surpassing skill. And though it cannot be doubted, that the chemical views which prevailed around him had a latent influence on his classification in some cases, he resolutely refused to bend his system to the authority of chemistry. Thus,[44] when he was blamed for having, in opposition to the chemists, placed diamond among the earthy fossils, he persisted in declaring that, mineralogically considered, it was a stone, and could not be treated as anything else.