$98 Introduction to the Study of Mineralogy . 



ledge to which they lead appertains too closely to mineralogy 

 to be omitted in a treatise relative to this last science. I 

 shall confine myself to the mention of some general facts, 

 the existence of which is confessed by several celebrated ge- 

 ologists; and ?hall subjoin an abridged description of the va- 

 rious aggregations known by the name of rocki, and of 

 others which are nothing else than grouped or mixtures of 

 mincralogieai species. Those who desire more detailed no- 

 tions mav derive them from the works of Deluc, Saussure, 

 Dolomieu, Pallas, Ramond, and other scientific men who 

 have seen Nature upon a large scale, and have acquired from 

 her a right to describe her phenomena. 



But independently of those who are led by a particular 

 taste towards researches which are the result of travels 

 and voyages, there exist men every where, who, while re- 

 siding in towns, are desirous of procuring useful informa- 

 tion respecting the various mineral productions of Nature ; 

 and mineralogy has this advantage over the animal and ve- 

 getable kingdoms, that the collections of objects connected 

 with it are more plentiful, and susceptible of fewer chasms, 

 on account of the smaller number of species,, while they are 

 also less exposed to deterioration, and may be studied with 

 delight at all seasons and in all places. I have flattered my- 

 self that there would be found in this work an additional 

 facility for acquiring the knowledge so proper for adorning 

 reason and cultivating the mind, and for exciting in the 

 soul a becoming?; gratitude for the benefits conferred bv an 

 all-seeing Providence. With the view of attaining everv 

 object connected with the science, I have given, as often 

 as opportunity offered, an idea of the purposes to which 

 the minerals are applied, and of the processes employed by 

 artists in order to render them fit for the use of mankind. 



To return to the method which I have adopted in the 

 classification of minerals. In the first place I resolved to 

 direct my steps, as far as I could, by chemical results. 

 Where, in fact, can we find relations more proper for closely 

 connecting various mineral substances with each other,- than 

 those which are founded upon the existence of one identical 



principle } 



