264 HISTORY OF MINERALOGY. 



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 Arti- 

 ficial 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 CJiaract&ristic of the 

 Mineral Kingdom, which was published at Dresden 

 in 1820 ; and, though extending only to a few 

 pages, excited a strong interest in Germany, where 

 men's minds were prepared to interpret the full im- 

 port 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 under- 

 taking of Mohs. 



Such a collection of marks of classes, implied a 

 classification previously 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 



