30 MINSRALOGICAL SYSTEMS. 



ar properties of raclers, others on the chemical properties of mineral;?, and (hat 

 the Abbe really has, purfuant to his plan, (fee in the begin- 

 ning oF the volume of plates. La dijlribution methodujue des 

 viinernux, par clajfes, ordres. Genres et efpeces, the melhodical 

 diftribution of minerals intoclafTes, orders, genera, and fpecies) 

 united all that has hitherto been difcovered on mineralogy, 

 without falling into that confufion which has ever been im- 

 puted to other mineralogical writers, we are almoft aftoniflied 

 at his fuccefs. *' To clafs minerals, to furnifli the means of 

 difcovering to which clafs, genus, and fpecies a mineral under 

 examination belongs," are the two great problems which the 

 Abbe Hauy propofes for folution, 

 Clafllfication, He folves the firfl in following Bergman's method (founded 



TcftTeatton W ^" chemical properties) much improved by the immenfe pro- 

 extetnal charac-grefs which chemical analyfis has made lince the days of that 

 *"'* great chemlfl. In the folution of the fecond he follows Wer- 



ner's method (grounded on exterior chara6lers)but corroborated 

 by a multitude of new experiments, eafily made and brought 

 * to a furprizing degree of correflnefs by the Abba's own la* 



bours on the forms of cryftals. But I perceive that the im- 

 menfity of matter contained in this treatife is leading me from 

 that point which I had particularly in view, I mean cryftal- 

 lography. 

 Haviy's defcrip- In the defcriptlon of crytlals the Abbe employs three dif- 

 tion of cryftals, ferent mean?. 1(1 He draws their figure; he does not give 

 tionJ '^^ ' cryftallographical tables as Rome de L'Ifle, which are only 

 general properties, but draws feparately each fpecies and va- 

 riety. Every form given in the plates has been examined by 

 himfelf; he has calculated every angle, and neverthelefs his 

 plates contain one third more figures than De L'Ifles tables. 

 2. By fymbollc 2d He makes ufe of fymbolic figns, than which nothing can be 



figns defignating ^^^^ fimple, and were invented not to recall the form of the 

 the laws or their ' , , , , . , - i i i j 



produftion. cryftal to the mind, but the laws by which it has been produced* 



Yet I have met with perfons, who were foaccuflomed to thefe 



figns, that at firfl fight of them they could immediately figure 



to themfelves the form of the correfponding cryfials. Thefe 



figns can alfo be fpoken, and much circumlocution in eonfe* 



3. By nomen- quence avoided. 3d A fignificant nomenclature fubdivided 



clature. into general and particular. The general is for the mineralsy 



and comprifes only fubdantives; the particular for the crj/Jiahi 



and is entirely cortlpofed of adjedlvesi He ftudioufly avoided 



4. introducing 



