INTRODUCTION. Xlll 



retention, in their systems, of the four gradual divisions of 

 the logicians, into classes, orders, genera, and species ; and 

 that, to a certain degree, they thereby do violence to nature. 

 I, nevertheless, believe that in this respect we may determine 

 something certain ; that is to say, how many degrees there 

 are in the division of minerals according to their constituent 

 parts : but as this is not the place to enlarge on this subject, 

 I shall reserve it for another occasion, since, in regard to the 

 subdivisions, it is always well to preserve those once intro- 

 duced. 



f( I shall observe, in the second place, that mineralogists 

 are little agreed, and are even undecided, with regard to 

 what they call the species : if we would take this word in a 

 determined sense, in general, all minerals that essentially 

 differ from one another in the relations of their composition 

 form different species ; and all those that essentially assimilate 

 in these relations, should be considered as forming one sole 

 species. Moreover, all the separate pieces of one species are 

 individuals*, to which we substitute the word species, because 

 it is impossible to have at the same time the entire species 

 which comprises all the mineral individuals which may be 

 found buried under the earth, or upon its surface. In short, 

 all the minerals by which one species passes into another, 

 atid which accidentally differ in one or other of its charac- 

 ters, are varieties."-^ 



The division into Genus and Species seems, as Werner here Species of 

 justly observes, to have been first conceived by the writers logicians. 



* This word is a further proof of the absurdity of the classification ; for a 

 plant or an animal may be an individual, but a mineral may always be divided 

 ad infinitum. 



f Werner, Traite* des Caracteres Exterieurs des Fossiles, trad, de Madame 

 Picardet, Paris, 1790, 8vo. p. 918. 



The German terms used by Werner (see Principes de Mineralogie, par 

 Berthout et Struve, Paris an 3,) are Geschkchter for Genus ; Gattungen for 

 Species ; Arten for Sub-species. The first (see Schwan) means germs, species, 

 race, nay genders, nation. The second, sort, manner, species of animals. 

 The third, sort, species, race, nature, complexion, air, manner, custom, 

 fashion. 



