Oh Cnjstallogrciphy, 26$ 



of tTic language of the science all the changes which should 

 not produce too many inconvenicnc(:s. 



But in order the better to show the advantages of those 

 which I have fixed upon, it will not He useless to explain^ 

 before any thing else, the principles to which, in my 

 opinion, the formation of names independent of analysis 

 ought to be subjected. 



For a long time, persohs have been irt the habit of giving 

 to mineral substances, names borrowed from those of thti 

 places uhere they were discovered. It seems to me that 

 this is to invert the use of these names, which ought only 

 to serve for designating individuals or particular bodies, as, 

 when speaking of an idiocrasis the locality of which we 

 wish to point out, we say that it is an idiocrasis from Ve- 

 suvius, or an idiocrasis from Siberia. If we substitute 

 instead of idiocrasis the term vesiwiaii, which is adopted 

 in Germany, the former expression will have the air of a 

 j;' -onasm, and the second will appear contradictory. 



Others derive the new denominations from the colour 

 nnder which the substance is presented to the first observers. . 

 This is to transfer to the species the name of the variety. 

 Tor example, yanoliie (violet stone) is the substance which 

 we call axinile. But there are crystals of this substance 

 which are green, and in this case the name of green yanolite 

 merely expresses an imaginary substance. 



We ought also to avoid confounding the name of on,e 

 mineral with that of another, with a different inflection; as 

 when persons called hyacintliine the substance whiclv we 

 call idiocrasis, without doubt in order to recall the ap- 

 pearances ascribed to it in common with the hyacinth (zir- 

 con in tliG present system), with which it had been at first 

 united. The truth is, that it differs from it very sensibly, 

 cither by its component principles or its structure, or everi 

 by the angles of its crystals ; and it is sufficient to regard 

 it for a moment in order to decide with Rome de I'lsle, 

 that they ought to be separated from each other. So far 

 therefore from indicating by the resemblance of the names 

 a pretended connexion, which to good eyes does not exist, 

 we ought rather to mark betv/een the two substances a di- 

 stinct line of separation, by a new name which could have 

 nothing in common with the first, and which would make 

 ns forget, if possible, an error which mineralogists ought 

 never to have committed. 



With respect to insignificant names to which several na- 

 turalists give the preference, there is nothing to prevent their 

 adoption. Of this number are the names derived from fable, 



l\ 4 SlicU 



