I'ilEFACE. IX 



The geographic distribution of mineral species 

 is of far less importance than the distribution of 

 plants or animals, in which so much depends on the 

 geographic position, climate, soil, the particular 

 place of growth or residence, and other accidental 

 circumstances. It is the subject of the fourth class 

 of observations, which are confined to the state- 

 ment of a few localities only, since it cannot fall 

 within the scope of an elementary work to enumerate 

 all the localities of the different varieties of the 

 species. 



Under the fifth head, some of the applications of 

 the species are mentioned, and sometimes a sixth 

 number is added, containing notices of species, 

 nearly allied to the one just treated of, but which 

 have not yet been received into the system. Some- 

 times one or several of these classes of observations 

 are wanting, or joined in a single number. 



The first Appendix, which follows immediately 

 after the system, contains such minerals as will 

 probably, when farther examined and compared, 

 be received into the system as particular species. 

 They are arranged in alphabetical order ; and in 

 some of them the order, or even the genus, is 

 mentioned, to which they will probably be found 

 to belong. Their great number cannot surprise 

 those who are aware how imperfectly many minerals 

 which were long ago known, have been hitherto ex- 



