566 On Crystallography. 



agreed as to the utility oi' a change. But naturalists, tv'ho 

 attcr long consideration undertake a task so painful, so 

 fastidious, and so little calculated to indemnify them for 

 their trouble, ought to have nothing but science in view, 

 desiring no advantage but that of being useful, and dreading 

 the reproach alone of not having done all that a true re- 

 gard for science demands of ihem. 



To conclude : — Those who would siill cherish a predi- 

 lection for the suppressed denominations, will f^nd them in 

 the same line with those which I have substituted, and may 

 Still continue to use them. But I hope that beginners, on 

 comparing both nonicnclaturcs, will store their memory, ac- 

 cordmg to my plan, with names so constructed as to en- 

 lighten their minds. I have taken care to add to these 

 names their etymologies, and I have done the same vviili 

 all the rest, whether new or old, whenever ibcre was a pos- 

 sibility of ascertaining their origin. 



OF THE NOMENCLATURE OF CRYSTALS. 



If the language of mineralogy has been so long defective, 

 from the bad choice of specific names, the almost total de- 

 ficiency of names with respect to the varieties of crystalli- 

 zation has left a void, which was no less an inconvenience. 

 There was no exception, except with respect to a small 

 number of these varieties, the forms of which were so 

 simple that they would suggest as if of themselves the 

 epithets of cubical, octahedral^ dodecahedral, he, which 

 Ought to be added to the names of the species. The more 

 compound forms were indicated by definitions, the length 

 of which was in some measure proportional to the number 

 of the facets; or, if it was warited to abridge these defini- 

 tions, by borrowing them from a resemblance between the 

 crystal and some familiar object*, this was done with so 

 little rationality, that it would have been desirable for the 

 honour of the comparison if such names were less known. 



Convinced of the necessity of introducing the utmost 

 precision into this part of mineralogical language, so much 

 neglected hitherto, J have ai tempted to desiornate the va- 

 rious crystalline forms by simple and significant names, 

 taken from the characters of these forms, or from the pro- 

 perties which i;esult from their structure, dnd from the 

 laws of. decrement on which they depend. 1 shall herb 

 present rrry readers with the series of these names, undei- 

 the form of a methodical system. I hope that those who 

 peruse it with attention will find an assistant for engraving 



* The following are exatnples of this kind : nad-hcaied calcareous spar, 

 dog'loullud calcareous spar, ^q, 



the§^ 



