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X. On CnjstaUography. Bi/ M. Hauy. Translated from 

 the last P-aris Editmi of Ids Traite de Mineralogie*. 



ADVERTISEMENT. 



Qf the Synonymies employed in the following Treatise^ and 

 other Objects of Detail. 



OrNONYMiES are as it were rallying points between, the va- 

 rious authors who write upon one and the same natural sci- 

 ence. J am fully aware how indispensable it is to attend to 

 them, particularly in a work containing a certain number of 

 new denominations. My greatest difficulty was to procure 

 names, which in the German language correspond with 

 those by which we designate the different mineral species. 

 M. Leopold de Buch, a mineralogist of deserved celebrity, 

 was kind enough, during his stay in Paris, to visit the cabinet 

 of tbeSchoolofMines, and to arrange and ticket a collectionof 

 specimens, according to the method of theicelebrated Werner, 



The figures have been traced by the method of projections, 

 supposing the points ot viesv to be removed ad hifinitum. 

 The full lines represent the ridges situated in the part of the 

 solid, which will be turned towards the observer if he sees 

 it in the position to which the projection refers : the punc- 

 tured lines represent the ridges situated in the opposite part, 

 or that which an observer could not see, unless the solid was 

 diaphanous. 



In the figures relating to geometrical constructions, we 

 have represented the diagonal and other lines as ly'mg upon 

 the faces of the solid, by suites of partial lines which leave 

 small empty spaces between them: vide mr, cm, cr, 

 (fig. 4,) Plate IX t, and i^, ad, lf,fg,fs, (fig. 9,) ibid.; 

 and we have represented the axes and other lines which tra- 

 verse the solid, as well as those which are external, so far as 



* Tn compliance with the wishes of many of our scientific readers, we in- 

 tend to present the public with a translation of the first volume of M. Hauy's 

 celebrated worlc on Mineralogy, being that which contains his Crystallo- 

 graphy. The Introduction was given in our last volume. 



f Besides the usual Numbers on the plates, for reference in our own vo- 

 lumes, we shall preserve, on those which relate to Crystallography, M. Hauy's 

 Older of numeration, to prevent confusion. 



it 



