Chapter CXIII: Book XV: The Analytico-Classificatory Science

HISTORY OF MINERALOGY.

Κρύσταλλον φαέθοντα διαυγέα λάζεο χερσὶ,
Λᾶαν ἀπόῤῥοιαν περιφεγγέος ἀμβρότου αἴγλης,
Αἰθέρι δ' ἀθανάτων μέγα τέρπεται ἄφθιτον ἦτορ.
Τόν κ' εἴπερ μετὰ χειρὰς ἔχων, περὶ νηὸν ἵκηαι,
Οὔτις τοι μακάρων ἀρνήσεται εὐχωλῆσι.
ORPHEUS. _Lithica._

Now, if the bold but pious thought be thine,
To reach our spacious temple's inner shrine,
Take in thy reverent hands the crystal stone,
Where heavenly light in earthy shroud is shown:--
Where, moulded into measured form, with rays
Complex yet clear, the eternal Ether plays;
This if thou firmly hold and rightly use,
Not long the gods thy ardent wish refuse.

{{313}} INTRODUCTION.

_Sect._ 1.--_Of the Classificatory Sciences._

THE horizon of the sciences spreads wider and wider before us, as we advance in our task of taking a survey of the vast domain. We have seen that the existence of Chemistry as a science which declares the ingredients and essential constitution of all kinds of bodies, implies the existence of another corresponding science, which shall divide bodies into kinds, and point out steadily and precisely what bodies they are which we have analysed. But a science thus dividing and defining bodies, is but one member of an order of sciences, different from those which we have hitherto described; namely, of the _classificatory sciences_. Such sciences there must be, not only having reference to the bodies with which chemistry deals, but also to all things respecting which we aspire to obtain any general knowledge, as, for instance, plants and animals. Indeed it will be found, that it is with regard to these latter objects, to organized beings, that the process of scientific classification has been most successfully exercised; while with regard to inorganic substances, the formation of a satisfactory system of arrangement has been found extremely difficult; nor has the necessity of such a system been recognised by chemists so distinctly and constantly as it ought to be. The best exemplification of these branches of knowledge, of which we now have to speak, will, therefore, be found in the organic world, in Botany and Zoology; but we will, in the first place, take a brief view of the science which classifies inorganic bodies, and of which Mineralogy is hitherto the very imperfect representative.

The principles and rules of the Classificatory Sciences, as well as of those of the other orders of sciences, must be fully explained when we come to treat of the Philosophy of the Sciences; and cannot be introduced here, where we have to do with history only. But I may observe very briefly, that with the process of _classing_, is joined the process of _naming_;--that names imply classification;--and that even the rudest and earliest application of language presupposes a distribution of objects according to their kinds;--but that such a spontaneous {314} and unsystematic distribution cannot, in the cases we now have to consider, answer the purposes of exact and general knowledge. Our classification of objects must be made consistent and systematic, in order to be scientific; we must discover marks and characters, properties and conditions, which are constant in their occurrence and relations; we must form our classes, we must impose our names, according to such marks. We can thus, and thus alone, arrive at that precise, certain, and systematic knowledge, which we seek; that is, at science. The object, then, of the classificatory sciences is to obtain FIXED CHARACTERS of the kinds of things; and the criterion of the fitness of names is, that THEY MAKE GENERAL PROPOSITIONS POSSIBLE.

I proceed to review the progress of certain sciences on these principles, and first, though briefly, the science of Mineralogy.

_Sect._ 2.--_Mineralogy as the Analytico-classificatory Science._

MINERALOGY, as it has hitherto been cultivated, is, as I have already said, an imperfect representative of the department of human knowledge to which it belongs. The attempts at the science have generally been made by collecting various kinds of information respecting mineral bodies; but the science which we require is a complete and consistent classified system of all inorganic bodies. For chemistry proceeds upon the principle that the constitution of a body invariably determines its properties; and, consequently, its kind: but we cannot apply this principle, except we can speak with precision of the _kind_ of a body, as well as of its composition. We cannot attach any sense to the assertion, that "soda or baryta has a metal for its base," except we know what _a metal_ is, or at least what properties it implies. It may not be, indeed it is not, possible, to define the kinds of bodies by words only; but the classification must proceed by some constant and generally applicable process; and the knowledge which has reference to the classification will be precise as far as this process is precise, and vague as far as this is vague.

There must be, then, as a necessary supplement to Chemistry, a Science of those properties of bodies by which we divide them into _kinds_. Mineralogy is the branch of knowledge which has discharged the office of such a science, so far as it has been discharged; and, indeed, Mineralogy has been gradually approaching to a clear consciousness of her real place, and of her whole task; I shall give the history of some of the advances which have thus been made. They are, principally, {315} the establishment and use of External Characters, especially of _Crystalline Form_, as a fixed character of definite substances; and the attempts to bring into view the connexion of Chemical Constitution and External Properties, made in the shape of mineralogical _Systems_; both those in which _chemical methods of arrangement_ are adopted, and those which profess to classify by the _natural-history method_.

{{316}} CRYSTALLOGRAPHY.