MINERALOGY. 



827 



last class of Agricola's system comprehends mixed 

 and compound fossils: 1. Mixtures of stones and 

 juices (sued) ; 2. of earth and metal; 3. of stone and 

 metal ; 4. of juice, stone, and metal. To the second 

 and third divisions he refers the various ores. A 

 translation of Agricola's system into German was 

 published, with considerable additions, by Lehmann, 

 at Freyberg, in 1809. 



Most of the writers on mineralogy who succeeded 

 Agricola until the middle of the following century 

 adopted his system, occasionally making some trifling 

 alterations, in conformity to the slow progress of 

 chemistry. Becher (whose Physica Subterranea 

 was published in 1667) made the first important 

 innovation upon the classification of Agricola. He 

 considered water and earth as the remote, and vitre- 

 ous, inflammable and mineral earths (sal, sulphur, 

 mercurius), as the proximate constituent parts of all 

 minerals, which he accordingly arranged under three 

 classes ; the first comprehending those stones in 

 which the vitreous earth constitutes the principal 

 ingredient ; the second and third class containing 

 the substances in which the two remaining earths 

 predominate. Bromelius, who published a book 

 entitled Catalogus Rerum Curiosarum (Gothenburg, 

 1698), referred sulphur and the bituminous sub- 

 stances to the same class, which he called sulphured 

 and pinguid. Magnus von Bromel, a Swede, who 

 was the pupil of Boerhaave, published a system of 

 mineralogy Inledring til Kunscah om Mineralier, 

 &c. (Stockholm, 1730), in which he not only availed 

 himself of all the improvements made by his prede- 

 cessors, but also proposed a new chemical division of 

 stony substances into such as are refractory (apyri), 

 or calcinable, or vitrescible in the fire, to which 

 were added the figured stones (figurati). 



After Von Bromel, the great Swedish reformer in 

 natural history appeared, whose admirable views 

 respecting the philosophy of the natural sciences have 

 contributed more to the perfection of our science than 

 the labours of all who preceded him ; and yet Linnaeus 

 appears to have possessed but very little knowledge of 

 minerals, but the complete success with which he 

 applied the method of natural history to the vegetable 

 kingdom rendered it easy fgr subsequent naturalists to 

 apply his principles to the mineral kingdom. Lin- 

 naeus, too, has the merit of calling the attention of 

 naturalists to the important characters derived from 

 the diversity of crystallization. Mineralogy, how- 

 ever, remained, from the time of Linnaeus to that of 

 Werner, almost exclusively in the hands of chemists, 

 who appear to have regarded the science in no other 

 light than as an appendage of chemistry, and who, 

 while they degraded all regard to the natural pro- 

 perties of minerals, believed that chemical know- 

 ledge was alone capable of affording the basis of the 

 classification, nomenclature and diagnosis of the 

 mineral kingdom. To this class of the cultivators 

 of mineralogy belonged Henkel, Pott, Wallerius, and 

 Oonstedt. 



In 1774, Werner published his work On the exter- 

 nal Properties of Minerals (J'on den aussern Kenn- 

 zzichen de Fossilien)-~a work of great merit and 

 value at that juncture, as it served to call the atten- 

 tion of naturalists to the only correct method of 

 arriving at a knowledge of this department of nature. 

 The external characters of minerals had before 

 been almost wholly neglected ; in this work they 

 were described with uncommon minuteness, though 

 they were employed by him in his system without a 

 j ust regard to their relative importance. The greatest 

 defect, however, in the views of Werner arose from 

 his reluctance to ascertain the properties of minerals 

 through the aid of instruments. lie scarcely availed 

 liimsrlf of any other means than such as were derived 



directly through the eye, the hand, and the tongue. 

 Hence those characters, depending upon the value 

 of angles and different degrees of hardness and speci- 

 fic gravity, and which are now acknowledged to be 

 of the highest value in mineralogy, were turned to com- 

 paratively little account. For a knowledge of Wer- 

 ner's system of mineralogy, we are indebted to his 

 translation of Cronsted's mineralogy (to which he 

 subjoined notes), to his catalogue of the mineral col- 

 lection 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 pub- 

 lished 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 chemi- 

 cal nature of their component parts. These he distin- 

 guishes 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 forma- 

 tion of the genera, these, as well as the species, hav- 

 ing 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 repre- 

 sentation of a pure science, an objection which 

 applies with scarcely undiminished force to the next 

 great system, which was presented to the mineral- 

 ogical world by Haiiy at the commencement of the 

 present century. Mineralogy, however, is under im- 

 mense obligations to the abbe Haiiy for his researches 

 respecting the geometrical character of minerals. 

 His labours, 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 know- 

 ledge 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 con- 

 nexion 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 mole- 

 cules of which are similar to each other, and have 

 the same composition." The following outline of 

 Haiiy 's system is taken from his Traite de Miner- 

 alogie (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 appen- 

 dix, 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 HI. True 



