to be of the highest value in mineralogy, were turned to comparatively little account. For a knowledge of Werner's system of mineralogy, we are indebted to his translation of Cronstedt's mineralogy (to which he subjoined notes), to his catalogue of the mineral collection of M. Pabst von Ohain, and to several memoirs in the Bergmannische Journal. In addition to these sources, several expositions of his system have been made by his pupils, the best of which is that published by professor Jameson. The fundamental principle laid down by Werner in the classification of minerals, is their natural affinity, which he allows to be founded on the chemical nature of their component parts. These he distinguishes into essential and accidental component parts, of the former of which only does he take notice in his arrangement. The essential component parts are subdivided into predominant and characteristic ones, and generally the characteristic happen to be, at the same time, the predominant constituents. His classes are four, which are founded on what he calls the fundamental constituent parts, viz. the earthy, saline, inflammable and metallic, each class being named after that fundamental constituent part which predominates in and characterizes it. Thus he derives his classes of earths, salts, inflammables and metals. These classes are subdivided into genera, which are founded upon the variety in the component parts of the minerals comprehended in each class, there being as many genera as there are predominating, or, at least, characteristic constituent parts discovered in their mixture. But neither Werner nor his pupils have been very strict in adhering to this rule for the formation of the genera, these, as well as the species, having more frequently been established by them upon the natural instead of the chemical properties. Werner's system was essentially deficient in respect to unity, in consequence of the regard which he allowed to the chemical relations of minerals, and, like those which preceded his time, it was rather a mixture of chemistry and mineralogy than the representation of a pure science, an objection which applies with scarcely undiminished force to the next great system, which was presented to the mineralogical world by Hauy at the commencement of the present century. Mineralogy, however, is under immense obligations to the abbé Haiy for his researches respecting the geometrical character of minerals. His labors, connected with crystallography, gave an

entirely new aspect to the science, and communicated to its results a degree of that precision and certainty which belong to geometry. Still his want of knowledge of the principles of natural history prevented him from remedying the faults of his predecessors. His system, like that of Werner, is founded upon two sciences, and consequently wants the order, the connexion and consistency of parts which belong to the idea of a science. He defines a species in mineralogy to be "an assemblage of bodies,the integrant molecules of which are similar to each other, and have the same composition." The following outline of Haiiy's system is taken from his Traité de Minéralogie (Paris, 1822):— Class I. Free acids. Class II. Metallic substances, but destitute of a metallic appearance. This class contains eight genera, viz. lime, barytes, strontites, magnesia, alumine, potash, soda, and ammonia; and to it is subjoined an appendix, consisting of one order characterized by the presence of silex in all its compounds, and which embraces a larger number of species than the whole class to which it is appended. Class III. True metallic substances. This class contains 18 genera, characterized by the different metals. Class IV. Unmetallic, combustible substances.-In proceeding to notice the labors of professor Mohs, we come to an era in the history of mineralogical science. This eminent philosopher, no less distinguished as a cultivator of the mathematics than of mineralogy, published at Dresden, in 1822, his Grundriss der Mineralogie, a work replete with new and philosophical views of our science. His first object is to fix the exact limits of mineralogy, and to exclude from it a variety of foreign matter belonging to other sciences, which had before rendered it a heterogeneous mass of information, incapable of derivation from constant principles by any regular process of reasoning. He then proceeds to develope the science under the following heads:-1. terminology; 2. theory of the system; 3. nomenclature; 4. characteristic; 5. physiography. Under the first of these he explains those properties of minerals which manifest no change, either in the properties themselves, or in the substances which possess them during their observation or examination, and which properties alone form the object of consideration in mineralogy, viewed as a pure science. They had before been treated of under the denomination of external or physical characters, though, from the stress which had been laid upon chem

ical characters, the greater part of them had been but very imperfectly determined; and this part of the subject is called terminology, because, besides the general investigation of those properties, it embraces also the explanations of the expressions which, for the sake of precision, are used in a determinate and peculiar sense. Decomposed and imperfectly formed minerals, or those which are destitute of several of the properties peculiar to these bodies, are not regarded as suitable objects for the consideration of the science; in which respect they are treated like mutilated, defective or monstrous plants or animals in botany and zöology. And in order to study the productions of the mineral kingdom in their purest state, Mohs takes notice of those properties which belong to minerals occurring in single individuals, separately from those which belong to several individuals of the same quality, formed in a common space, one being the support of, or at least contiguous to, the other, of the former of which only does he make use in the determination of the species, while he pays no attention to the properties of minerals composed of individuals belonging to different species (mixed minerals), these last falling within the province of geology. This is a distinction of the highest importance and utility, in rendering all the departments of mineralogy mutually consistent, though one which had been almost wholly disregarded by all his predecessors. According to this system, the individual of the mineral kingdom, or the simple mineral, is the sole object of mineralogy, and the natural properties of the simple mineral are the only ones to which, in this science, we ought to direct our attention. It will be obvious, therefore, that all information thus derived must be of one kind, and consequently its aggregate conformable to the logical idea of a science. Mohs has particularly distinguished himself in treating of that part of terminology which relates to the regular forms of minerals. The fundamental forms, from which he derives all the occurring forms among minerals, are but four in number, viz. the scalene four-sided pyramid, the isosceles four-sided pyramid, the rhombohedron, and the hexahedron; and the geometrical constructions by which he illustrates the simple forms capable of appearing in the individuals of one and the same species, or which may produce combinations with one another, entitle him to the first rank as a crystallographer. The natural-historical properties of compound minerals are

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treated of in the most precise manner, the previous neglect of which had involved the science in numerous important errors. But one of the greatest improvements under this head was the establishment of an accurate scale for the degrees of hardness. This was effected by choosing a certain number of suitable minerals, of which every preceding one is scratched by that which follows it, while the former does not scratch the latter; and the degrees of hardness are expressed by means of numbers prefixed to the different individuals of the scale. Thus

1 expresses the hardness of talc ;

2

3

The second general head under which mineralogy is developed, according to Mohs, is the theory of the system, which contains the reasoning or philosophical part of the science. It determines the idea of the species; fixes the principle of classification; and upon the idea of the species it founds, according to this principle, the ideas of the genus, the order, and the class; and lastly, by applying all these ideas to nature, the outline of the system thus constructed is furnished with its contents, in conformity to our knowledge of the productions of nature, as obtained from immediate inspection. The idea of the species is here, for the first time, scientifically obtained, and is founded upon all the series of natural properties without the introduction of any considerations foreign to natural history, which had proved the source of the contamination that the science had before suffered from heterogeneous principles. The principle of classification consists in the resemblance of natural properties, since in every science the classification must rest upon such relations as are objects of the science. On the different degrees of resemblance are founded the higher ideas of the theory of the system. An assemblage of species connected by the highest degree of natural-historical resemblance is termed a genus; an assemblage of similar genera an order; of similar orders a class; and the collection of these ideas conformably to the degree of their generality, and applied to the productions of the mineral king

dom, constitutes the mineral system. The mineral system is therefore the systematic exhibition of the natural resemblance as observable in the mineral kingdom, or of the connexion established by nature among its products by means of this resemblance. For this reason it is called the natural system, because, in fact, it expresses nature in this very remarkable relation. The third idea of the science, as developed by Mohs, is its nomenclature, which relates to the connexion of its unities with certain words, through which the ideas and representations may be so expressed as to be conveniently applied in writing and speaking. Nothing is better calculated to furnish us with an idea of the situation in which mineralogy had before been placed, than the consideration of its former nomenclature, and of the method employed in giving new names. Those were regarded as the best which had no signification, as is obvious from the frequency with which designations were adopted derived from colors, persons, localities, and other accidental circumstances; and, as respects those names which referred to the connexion of the different minerals in regard to their resemblance, these were still more objectionable, since the connexion expressed by them was either entirely incorrect, or without reference to the system in which the names were applied. The nomenclature therefore required to be wholly remodelled, none deserving of the name having before existed, the reason of which appears to have been that mineralogy had not before been treated as a science, but as an aggregate of various kinds of information, a sort of mixture which would admit every kind of knowledge to be introduced, and in which nothing could be placed wrong, because in such a disposition there could be no order. The order is the highest idea expressed in the nomenclature of Mohs, and in the selection of the names of the orders he has invented but two which are entirely new, having employed as many designations from ancient mineralogy as would answer the purpose. The names receive their signification in agreement with the ideas of the orders; thus pyrites embraces the minerals hitherto called by that name. A mineral which may with propriety bear the name of a metal must really be a metal, or it must present the properties peculiar to metals. Mica signifies a mineral which may be cleaved with facility into thin, shining laminæ ; the order mica therefore contains only such species as present cleavage in a

high degree of perfection. The name of the genus is a compound name, formed by connecting another word with the name of the order. Thus we have lead glance, augite spar, iron pyrites. The generic name also refers to the properties of the genus, and expresses, as much as possible, some striking feature of its resemblance with other bodies. Such is the name garnet-blende. The genus designated by this name belongs to the order blende; the individuals which it contains very often look like garnet. The denomination of the species is produced by the nearer restriction of the generic name by an adjective. The adjective with which the species is designated within its genus is taken from its natural properties, and in general refers to one of those properties of the species which is most useful in distinguishing it from other species of the same genus; hence the systems of crystallization and the relation of cleavage are the most frequently employed,-examples of which are hexahedral, prismatic, rhombohedral iron pyrites; rhombohedral, octahedral, dodecahedral, prismatic iron ore, &c.— The great advantage of the systematic nomenclature is, that the names produce an image of the objects to which they refer, which the trivial nomenclature can never do; for example, if we hear the name peritomous titanium ore, and have only an idea of the order ore, this at once will produce a general image of the species, which will be still more restricted if we have some idea of the genus titanium ore; but, on the other hand, if we hear the name rutile, and do not know the species itself to which it belongs, we never can imagine any thing like a representation of the object, though, for the rest, our knowledge of mineralogy may be very extensive. The terminology, the theory of the system, and the nomenclature, form the constituents of theoretical mineralogy. Practice, or the application of it to nature, requires the characteristic, the object of which is, to furnish us with the peculiar terms or marks, by which we are able to distinguish objects from each other, so far as they are comprehended in the ideas established by the theory of the system. In order to find the name of a mineral when its properties are ascertained, we make use of the characteristic, which consists of an assemblage of general ideas, corresponding to the system, and expressed by single distinctive marks. With these ideas are connected the names and denominations as far as the nomenclature extends and requires, not above the order,

nor below the species; and they are by degrees transferred to the individual, in proportion as it enters within the compass of those general ideas. The characteristic is only useful when we have the mineral in our hands, and is not to be studied to obtain a knowledge of the contents of the mineral kingdom, since the characters of its classes, orders, genera and species, consisting of single marks or properties, are not calculated to produce representations or images of the objects to which they refer. Physiography, the last head of scientific mineralogy, consists of the assemblage of the general descriptions, and is intended to produce a distinct image of minerals. We cannot, by its assistance, find the place of a given mineral in the system, or, in other words, recognise it; for it is independent of that connexion, among minerals, upon which the system is founded. Mohs was the first writer who drew the line between the determinative and the descriptive parts of mineralogy—a distinction which is of the utmost consequence to the perfection of the science. The foregoing heads or departments of mineralogy are all equally important and indispensable for conferring upon the science the character of a whole, though, in the application of the science, the parts are used separately, and, in a measure, independently of each other, according to the object in view. Those who wish to determine an individual occurring in nature, will find the characteristic the most important department, for neither of the others can be of the least use to them; while those who intend to arrive at a general conception of the species from knowing its name, or one of the individuals belonging to it, will find their views forwarded only by the physiography; for neither the characteristic nor any other department of mineralogy, contains any information answering the

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dom, solely by making it correspond to the philosophical idea of a science. It contains merely natural-historical information; i. e. such as proceeds from a comparison of natural-historical properties, and all the rest is foreign to it. The developement of the whole, in its single departments, is in itself systematical; and what it contains of real systems, the systems of crystallization, and the mineral system itself, really deserve that name; because they are the result of the application of one single idea to the whole compass of a certain kind of information. The science itself forms a whole, being intimately connected in all its departments, and strictly separated from all other sciences, which is a necessary consequence of a systematic mode of treatment. The method employed is so simple, that, on that very account, it is immutable; nor can there be any doubt, that other methods, compounded of different principles, from the want of consistency prevailing in their different departments, will finally also be reduced to this method. We conclude our abstract of the system of Mohs, by presenting the reader a list of his genera, as represented in the translation of the Grundriss der Mineralogie, by Haidinger (Edinburgh, 1825).

veloped, fulfils perfectly the demands which natural history makes of its several departments. But it enables us to answer no question which lies beyond the limits of natural history. Nobody will ever be able to infer from the mere natural-historical consideration of a mineral, any thing with regard to its chemical, geological, or economical properties. The natural history system has its provinces exactly determined, within which it serves every purpose, but admits of no application without; and these commendable properties are conferred upon mineralogy, as the natural history of the mineral king

3. Nitre salt. 4. Rock salt. 5. Ammoniac salt. 6. Vitriol salt. 7. Epsom salt. 8. Alum salt. 9. Borax salt. 10. Brythine salt.

CLASS II.

ORDER 1.-Haloide. Genera. 1. Gypsum haloide. 2. Cryone haloide. 3. Alum haloide. 4. Fluor haloide. 5. Calc haloide.

ORDER 2.-Baryte. Genera. 1. Parachrose baryte. 2. Zine baryte. 3. Scheelium baryte. 4. Hal baryte. 5. Lead baryte.

510

Genera.

ORDER 9.-Metal.

1. Arsenic. 2. Tellurium. 3. Antimony. 4. Bismuth. 5. Mercury. 6. Silver. 7. Gold. 8. Platina. 9. Iron. 10. Copper.

ORDER 10.-Pyrites. Genera. 1. Nickel pyrites. 2. Arsenic pyrites. 3. Cobalt pyrites. 4. Iron pyrites. 5. Copper pyrites.

ORDER 11.-Glance. Genera. 1. Copper glance. 2. Silver glance. 3. Lead glance. 4. Tellurium glance. 5. Molybdenum glance. 6. Bismuth glance. 7. Antimony glance. 8. Melane glance.

ORDER 2.-Coal.

Genus. 1. Mineral coal.

Among the works on mineralogy, the following are worthy of notice: Traité de Mineralogie, par A. Brongniart (Paris, 1807); a Familiar Introduction to the Study of Crystallography, by Henry James Brooke (London, 1823); an Elementary Introduction to the Knowledge of Mineralogy, &c., by William Phillips (London, 1823); Handbuch der Mineralogie, von C. A. S. Hoffmann (Frieberg, 1811, and continued by A. Breithaupt); Mohs's System of Mineralogy, translated by William Haidinger (Edinburgh, 1825); Traité de Crystallographie, par M. l'Abbé Hauy (Paris, 1822); Traité de Minéralogie,

M. l'Abbé Hauy (Paris, 1822); Handpar buch der Oryklognosie, von Karl Casar von Leonhard (Heidelberg, 1826); Brewster's Treatise on Mineralogy (Edinburgh, 1827); Die Mineralogie der A. Hartmann (Ilmenau, 1829). The study of minerals has received considerable attention during the last twenty years, in the U. States, though, for the most part, that attention has been devoted to the discovery of localities and the formation of cabinets. Already we have discovered nearly all the species found in other quarters of the globe, as may be noticed by consulting the different articles in the department of mineralogy in this work; and several entirely new species have been added to the science by American mineralogists. The only considerable work upon the science which has as yet appeared in the U. States is that of professor Cleaveland, and which was founded, for the most part, on the systems of Brongniart and Hauy. It has passed through two editions, and its author is now understood to be preparing an improved edition for the press.

MINERAL WATERS are those waters which contain such a proportion of foreign matter as to render them unfit for common use, and give them a sensible flavor and a specific action upon the animal economy. They are very various, both in their composition and temperature, and, of course, in their effect upon the system; they are generally, however, so far impregnated with acid or saline bodies as to derive from them their peculiarities, and are commonly divided into four classes: acidulous or carbonated, saline, chalybeate or ferruginous, and sulphureous. In regard to temperature, they are also divided into warm, or thermal, and cold. The substances which have been found in mineral waters are extremely numerous, but