REFORM OF MIXERALOGICAL SYSTEMS. 35 



aaupt 4 attempted to discover the ingredients of minerals by their 

 peculiarities of crystallization. The persuasion that there must be some 

 connexion between composition and properties, transformed itself, in 

 their minds, into a belief that they could seize the nature of the con- 

 nexion by a sort of instinct. 



This opinion of the independency of the science of external charac- 

 ters, and of its sufficiency for its own object, at last assumed its 

 complete form in the bold attempt to construct a system which should 

 borrow nothing from chemistry. This attempt was made by Frederick 

 Mohs, who had been the pupil of Werner, and was afterwards his suc- 

 cessor in the school of Freiberg ; and who, by the acute and methodical 

 character of his intellect, and by his intimate knowledge of minerals, 

 was worthy of his predecessor. Rejecting altogether all divisions of 

 which the import was chemical, Mohs turned for guidance, or at least 

 for the light of analogy, to botany. His object was to construct a 

 Natural System of mineralogy. What the conditions and advantages 

 of a natural system of any province of nature are, we must delay to 

 explain till we have before us, in botany, a more luminous example of 

 such a scheme. But further ; in mineralogy, as in botany, besides the 

 Natural System, by which we form our classes, it is necessary to have 

 an Artificial System, by which we recognize them ; a principle which, 

 we have seen, had already taken root in the school of Freiberg. Such 

 an artificial system Mohs produced in his Characteristic of the Mineral 

 Kingdom, which was published at Dresden in 1820 ; and which, though 

 extending only to a few pages, excited a strong interest in Germany, 

 where men's minds were prepared to interpret the full import of such 

 a work. Some of the traits of such a " Characteristic " had, indeed, 

 been previously drawn by others ; as for example, by Haiiy, who notices 

 that each of his Classes has peculiar characters. For instance, his First 

 Class (acidiferous substances,) alone possesses these combinations of 

 properties ; " division into a regular octohedron, without being able to 

 scratch glass ; specific gravity above 3'5, without being able to scratch 

 glass." The extension of such characters into a scheme which should 

 exhaust the whole mineral kingdom, was the undertaking of Mohs. 



Such a collection of marks of classes, implied a classification pre- 

 viously established, and accordingly, Mohs had created his own mineral 

 system. His aim was to construct it, as we shall hereafter see that 

 other natural systems are constructed, by taking into account all the 



4 JDre.idn, Auswahl, vol. ii. p. 97 



