Natural History. 1 49 



€0 much distinguished, was pursued farther by suc- 

 ceeding chemists, and particularly by M. Vauque- 

 LiN, of France. 



AV^hile this astonishing progress was making in 

 mineralogy, by means of chemical inquiry, the at- 

 tention to external characters, which had been for 

 some time out of vogue, began to be resumed, 

 and led to considerable improvements in the diag- 

 nostic rules, and in the nomenclature of the science. 

 For this we are chiefly indebted to the celebrated 

 Werner, of Germany, who certainly holds a place 

 among the .most distinguished mineralogists of the 

 age. Though he did not wholly neglect the che- 

 mical properties of fossils, he devoted his chief at- 

 tention to their external characters, and made these 

 the principal foundation of his arrangement. He 

 and his disciples insisted, that the colour, shape, 

 lustre, transparency), texture, cohesion, density, feel, 

 and general hahitude of mineral substances, furnish 

 abundantly sufficient indications for distinguishing 

 and arranging them, And, indeed, the ingenuity 

 and skill with which they selected these charac- 

 ters, the judgment and accuracy with which they 

 learned to apply them, and their wonderful success 

 in forming a luminous system on the principles 

 which these sensible qualities afforded, must be 

 considered as pointing out one of the most im- 

 portant periods in the history of mineralogy. 



Before this period the nomenclature of mineral 

 bodies had been in a very perplexed and imperfect 

 state, insomuch, that while rich stores of know- 

 ledge respecting them were possessed by many, it 

 was extremely difficult to convey this knov/ledge, 

 for want of precise definitions and descriptions. 

 The same substance, from some slight variations 

 in appearance, was often called by different 

 names; and different substances, from some affi- 

 nities of external character, by the same name. 



