464 Introduction to the Study of Mineralogy, 



possible number of species, and by taking ad va vantage of 

 the recent discoveries which have enriched mineralogy- 

 I here testify my gralitude to those ingenious foreigners to 

 whom I am indebted for some of the greatest rarities in my 

 collection, and particularly to Messrs. Abildgaard, Manthey, 

 Karsten, Neergaard, Esmark, Baron de Moll, Coden, and 

 Huffman- Liang. To some of these friends I also owe some 

 interesting observations, which have given additional value 

 to their presents. Nothing more strongly confirms what 

 has been so often said of the learned of all countries, namely, 

 that they form one family, than this division of riches, which 

 makes the distance between their respective countries disap- 

 pear, and this communication of light which renders them 

 constantly present with each other. 



All that I have said concerns the solution of the first of 

 the two problems I have mentioned, and its object is, the 

 classification of substances. Now analysis, which presents 

 data so advantageous for attaining this object, requires ope- 

 rations frequently long and delicate, and on that account 

 alone would become embarrassing, if it was necessary always 

 to have recourse to it, in order to resolve the other problem, 

 2. e, in order to recognize the substances. 



I now return to the employment of characters which, 

 being more easily ascertained, more convenient and expe- 

 ditious, may serve as a beacon to the minerals already classi- 

 fied. 



To judge of this according to the manner of viewing 

 things generally adopted hitherto with respect to the solution 

 of the problem in question, the simple description of mine- 

 rals by the helps of their external characters contains all 

 that is sufficient to distinguish them from each other. No- 

 thing has more contributed to establish the reputation of the 

 svstem in which these characters are employed, than the per- 

 fection given to it by Werner. This ingenious mineralogist 

 has presented it under the form of a complete system *, in 

 which every thing in a mineral that is capable of affecting 



* Vide Tabulae synsptica terminurum Systemalis oryctngnostici fferncriani, a 

 Gregorio Wad. Hafnice, 1798. See also Berthout and Struve's Principles o£ 

 Mineralogy, and the platei which accompany Brochant's Mineralogy. 



our 



