The system of Cronstedt was publish, ed in 1758, and for twenty years was generally received by the scientific world. In 1780, a translation of Cronstedt's mine. ral system appeared in Germany, accom panied with notes, by Werner, the Pro fessor of Mineralogy at Freyberg in Saxony. Six years before, the professor had published a separate treatise on the classification of minerals, in which he exhibited much skill in a method of de scribing them by means of external charac. ters. Werner's method is chiefly, if not wholly followed in Germany, and is high. ly regarded in this and other countries. This system was introduced here by Mr. Kirwan, in 1784, who further elucidated it some years afterwards by a new and much enlarged addition of his work. In preparing the latter edition, Mr. Kirwan had the advantage of consulting one of the completest and best arranged collec tions of minerals which had been made in any country. This was collected by Leske, and after him is called the Leskean collection. It was arranged between the years 1782-1787, according to the princi ples of Werner, and with his assistance. After the death of Leake, a catalogue of it was drawn up, which is divided into five parts : the first, which is denominated the characteristic part, consists of spe cimens intended for the illustration of the external characters of the classification. The second, which is the systematic or oryctognostic part, comprehends all sim ple minerals,distributed according to their genera and species, agreeably to the me thod at that time followed by Werner. The next is the geognostic geological part, which includes the substances found in the different kinds of rocks, as they are divided into primitive, transition, stra tiform, alluvial, and volcanic mountain. This part of the collection is very rich in petrifactions. The fourth part is intended to illustrate the mineralogy of every coun try on the globe, by exhibiting its mineral productions. The fifth part is called the economical collection, and is formed of specimens which are employed in arts and manufactures, as in architecture, sculpture, agriculture, jewellery, dyeing, clothing, pottery, glazing, enamelling, polishing of metals, furnace-building, me dicine, metallurgy, &c. This short ac count of a very valuable collection may be a guide to collectors and amateurs in the science. In France, the mineralogi cal treatises of Brochant, Hauy, and Brougniart, may be noticed ; these have already been referred to in the course of our volumes, but claim a distinct enume ration here. The system of Brochant is formed on the principles of Werner's classification, and is thought to be the most perspicuous account of the German mineralogy that has yet been published. The system of Hatay divides itself into four classes. The first class consists of substances which are composed of an acid united to an earth and alkali, and sometimes to both. The second class in cludes only earthy substances, but some times combined with an alkali : it con. stitutes the silicious genus of other sys tems. The third class comprehends com bustible substances which are not metals. The metals form the fourth class. This is divided into three orders, which are characterized by different degrees of oxy dation. Besides these classes, there are three appendices. The first contains those substances, the nature of which is not sufficiently known to have their places accurately assigned in the system. The second appendix includes aggregates of different mineral substances : and the third is devoted to the consideration of volcanic products.
The system of Brougniart includes sub stances which are not treated of by wri ters on mineralogy, and is divided into five classes. The first contains those sub stances, excluding the metals, which are combined with oxygen ; it contains two orders : the first including air and water ; and the second the acids. The second class treats of saline bodies, and compre hends the alkaline and the earthy salts.
The third class, containing stones, in cludes the hard, the magnesian, and the argillaceous stones. The fourth class con tains the combustible substances, viz. the compound and simple. The fifth class includes metals, which are separated into the brittle and the ductile.
The system of Werner, as given by Professor Jameson, has been chiefly ad hered to in this work, and a detail of the several genera will be found in their al phabetical order; it will therefore be suf ficient in this place, to give an outline of his system.
He has arranged the characters of mi nerals under four divisions : the external ; the internal or chemical ; the physical ; and the empirical. To the first belong the characters drawn from those proper ties which are obvious to the senses, such as colour, lustre, transparency, form, texture, hardness, and specific gravity : to the second, those which are derived from the chemical composition, or dis covered by any chemical change which the mineral suffers : to the third are re ferred those characters which are afford ed by certain physical properties, as elec tricity or magnetism ; and to the fourth, a few characters, derived from circum stances frequently observed with regard to a mineral, as the place where it is found, or the minerals by which it is usu ally accompanied.
Of these divisions, the external cha racters are considered as the most im portant, and it is chiefly with regard to them that so much labour has been em ployed on the language of mineralogy. The first property is colour, which, though but seldom highly characteristic, is one of the most obvious characters. It varies frequently in the same species, and is liable to change by very trivial fo reign circumstances ; it always enters, however, into the description. To give precise ideas of the different shades of colour, Werner has fixed on certain prin cipal or standard colours, to which the subordinate shades are referred ; defining them by means of an epithet, either ex pressive of the intermixture of one of the principal colours with the other, or derived from some substance familiarly known, the colour of which is constant. The principal charactersare white, grey, black, blue, green, yellow, red, and brown. Of these are numerous subordi nate colours, as bluish-grey, greyish-black, &c. These are not always well marked, but incline to, are intermediate, or pass into each other. The shade of colour is of different intensities, as dark, deep, light, and pale. Besides these, other va rieties are introduced, as dotted, striped, zoned, &c. and the colour is varied by scraping the surface, affording a charac ter called a streak.
Lustre denotes the relation which' a fossil bears to the reflection of the light from its surface. According to Werner, "resplendent" denotes the highest de gree of lustre, which is such as to be seen at a considerable distance ; "shining" is applied when the lustre, though perceiv ed at a distance, is not so well observed as on a near approach ; "glistening," when it is perceptible only at a very short distance; " glimmering," when some of the minute parts only of a surface reflect a weak light : and "dull," when lustre is entirely wanting. Different kinds of lustre are also marked, as the metallic, adamantine, vitreous, waxy, pearly, and resi nous.
Transparency is denoted by different degrees and terms; " transparent," is applied where objects can be distinctly perceived through the interposed sub. stance ; " semi-transparent, where ob jects are seen, but not distinctly, and this only through thin pieces ; " translucent," when light is in some measure transmit ted, but objects cannot be observed ; " opaque," when no perceptible light is transmitted : connected with transparen cy is refraction, which, in the greater number of minerals, is single, but in some double, the latter giving a double image when an object is surveyed through them.