34:6 HISTORY OF MIXEKALOGY. 



resemblances and differences of the objects classified. It is obvious 

 that to execute such, a work, implied a most intimate and universal 

 acquaintance with minerals ; a power of combining in one vivid sur- 

 vey the whole mineral kingdom. To illustrate the spirit in which 

 Professor Mohs performed his task, I hope I may be allowed to refer 

 to my own intercourse with him. At an early period of my mine- 

 ralogical studies, when the very conception of a Natural System was 

 new to me, he, with great kindliness of temper, allowed me habitually 

 to propose to him the scruples which, arose in my mind, before I could 

 admit principles which appeared to me then so vague and indefinite ; 

 and answered my objections with great patience and most instructive 

 clearness. Among other difficulties, I one day propounded to him 

 this ; " You have published a Treatise on Mineralogy, in which you 

 have described all the important properties of all known minerals. 

 On your principles, then, it ought to be possible, merely by knowing 

 the descriptions in your book, and without seeing any minerals, to con- 

 struct a natural system ; and this natural system ought to turn out 

 identical with that which you have produced, by so careful an exami- 

 nation of the minerals themselves." He pondered a moment, and then 

 he answered, "It is true; but what an enormous imagination 

 (cinbildungskraft, power of inward imagining], a man must have for 

 such a work ! " Vividness of conception of sensible properties, and 

 the steady intuition (anschauung) of objects, were deemed by him, and 

 by the Wernerian school in general, to be the most essential conditions 

 of complete knowledge. 



It is not necessary to describe Mohs's system in detail ; it may suf- 

 ficiently indicate its form to state that the following substances, such 

 as I before gave as examples of other arrangements, calcspar, gyp- 

 sum, fluor spar, apatite, heavy spar, are by Mohs termed respectively, 

 Rlwmbohedral Lime Haloide, Gyps Haloide, Octohedral Fluor 

 Haloide, Rhombohedral Fluor Haloide, Prismatic Hal Baryte. 

 These substances are thus referred to the Orders Haloide, and Baryte ; 

 to Genera Lime Haloide, Fluor Haloide, Hal Baryte ; and the Species 

 is an additional particularization. 



Mohs not only aimed at framing such a system, but was also ambi- 

 tious of giving to all minerals Names which should accord with the 

 system. This design was too bold to succeed. It is true, that a new 

 nomenclature was much needed in mineralogy : it is true, too, that it 

 was reasonable to expect, from an improved classification, an improved 

 nomenclature, such as had been so happily obtained in botany by the 



