[ m I 



XXXIII. OnCrystaUographTj. By M.Ua\5Y. Translated 

 from the last Paris Edition of his Traite cle Mineralogies 



[Continued from p. 153.J 

 OF MINERALOGICAL METHODS. 



xjLll the productions of nature, considered in the point of 

 view in which she presents them (Hrecily to our eyc», form 

 a picture complicated with a multitude of details, in the 

 midst of which the eye is lost at the first glance, and sees 

 everv thing at once without distinguishing any thing. 



With the view of facilitating the study of this picture, 

 there have been contrived, with respect to mineralogy, as 

 with zoology and botany, methodical distributions of the 

 subjects which are therein embraced ; their different pans 

 have been dissected in imagination, so as to form a kind of 

 factitious table, with which we may afterwards compare the 

 former, and which serves it as a kind of explanation. 



However slightly we reflect on the progress of these 

 methodical arrangements, we may easily perceive that thev 

 are founded on the faculty possessed by the human mind 

 of regarding certain qualitic? m an object, by abstracting 

 others; and of raising ourselves gradually from particular 

 to general ideas. 



Thus, when speaking of an oak as a determinate object 

 which I can point out with my finger, I make no abstrac- 

 tion ; I consider in the object which I name, all the qualities 

 that can accord with it : in a word, I designate an indivi- 

 dual, i. e.j a being which has a particular existence. But 

 if, in pronouncing the word oak, I have not seen any par- 

 ticular oak, then 1 abstract the idea of a particular ex- 

 istence ; I designate in general a collection of individuals 

 similar in all their parts, and this collection is what is called 



a SPECIES. 



The tiense in which I have taken the word Oak (or 

 Quercus) is that which every body attaches to it in ordinary 

 language. Now, on comparing the individuals of the 

 species in question with those of another species, to which 

 the name of Holm Oak {Iltx) has been given, I remark 

 that the latter have the organs of the flower similarly con- 

 structed, and that their fruits are acorns also ; but that they 

 ditfer from each other in several respects, and particularly 

 in the form and consistence of the leaves ; which in the 

 former are broad, soft, and tern)inated by round lobes, and 

 in the latter narrow and indented at the edges. I can, 

 tliercfore, fix n\y attention solely im the resemblance of the 



flower 



