390 IDIOPHYSICS. * 



whether it examines the stones from which the vegetable soil is 

 derived ; or the ores which yield the useful and precious metals ; 

 or the gems which grace the brow of beauty or the diadems of 

 kings. 



Aristotle and Pliny wrote vaguely on minerals ; but the first regu- 

 iar classification of them appears to have been made by Avicenna, 

 the alchemist ; who divided them into stones, metals, inflammables 

 and salts. A similar classification was made by Agricola ; and 

 another by Beccher, the first writer on Chemistry ; who regarded all 

 minerals as composed of salt, sulphur, mercury, earth, and water. 

 The first idea that certain minerals always crystallize in certain par- 

 ticular forms, may be traced to Gulielmini, in 1707 : but Linnaeus 

 had the merit of first pointing out the importance of crystallography, 

 in classifying and examining minerals. His views on this subject 

 were corroborated by the researches of De Lisle ; and especially by 

 the Abbe Haiiy, who first examined the cleavage of minerals, and 

 applied the atomic theory to account for their formation. Meanwhile, 

 Werner, in his work on the External Characters of Fossils, (as 

 minerals were then termed), in 1774, attained great precision in 

 describing minerals ; particularly by means of their color, lustre, 

 hardness, and specific gravity : but in classifying minerals, he adopted 

 a system, like that of Haiiy, partly natural, and partly chemical, as 

 first proposed by Cronstedt, in 1758. 



The views of Haiiy, concerning primary and secondary forms of 

 crystals, were corrected, in various instances, by Weiss ; who, in 

 1809, gave a new classification of crystals, forming several crystalline 

 systems, or groups, founded on the axes of figure, and such that 

 those of the same group might be derived from each other. This 

 true, and probably ultimate theory, was applied by Mohs to all the 

 known species of minerals ; and in his Outlines of Mineralogy, pub- 

 lished in 1822, it was made the basis of a natural classification of 

 minerals, closely resembling those of animals and vegetables now 

 prevailing. This system, as at present modified and simplified, 

 agrees so far with the chemical, as to show that it has a foundation 

 in nature ; although it doubtless admits of farther modifications and 

 improvements ; and although the mixed system has been adopted by 

 Brongniart, and more recently by Naumann of Freiberg, who excels 

 in the department of crystallography. The purely chemical classi- 

 fication, proposed by Berzelius, founded on the electric relations of 

 the chemical elements, has failed of giving a fixed character to the 

 science, or of coming into general use. In our own country, the 

 mixed system was adopted by Cleaveland ; but the natural classifica- 

 tion has been preferred by Dana, in his recent valuable work ; which 

 we here propose to follow, as far as our limits will allow. 



We proceed to give a brief synopsis of Mineralogy, under the 

 heads of Crystallography, and Idiographic, Systematic, and Descrip- 

 tive Mineralogy. 



1. The science of Crystallography, has for its object the exa- 

 mination of crystalline forms : and its connection with Mineralogy 

 arises from the fact that most of the crystalline forms, with which 

 we are acquainted, belong to simple minerals ; and that each mineral 



