312 MR HAIDINGER on the Determination of the Species in 



lysed specimen, and all the rest, agree in their natural-historical 

 properties, not because they are acted upon by heat, or other 

 chemical re-agents, in a similar manner ; for this would only be a 

 repetition of the first process, from the analysis of one specimen, 

 (however small), to infer the chemical constitution of the rest of 

 the individuals or varieties included in the species. 



It has often been urged, that the method of Professor MOHS 

 tended to depreciate the merits of Chemistry, by excluding its 

 influence in the determination of the species, and in the con- 

 struction of mineralogical systems. This is by no means a just 

 observation. Every one is aware, and more particularly those 

 who have made minerals their study, that it is chemistry, in its 

 various departments, which gives their labours a manifold inte- 

 rest, in supplying the link between their abstract considerations 

 and the wants and comforts of mankind. The only thing ob- 

 jected to by Mr MOHS, is that unnecessary and improper union 

 of chemistry and mineralogy, in other words, chemical mineralo- 

 gy ; which, so far from producing the good consequences so fre- 

 quently boasted of, may actually be considered as having retard- 

 ed the researches directed towards the knowledge of the proper- 

 ties which minerals present in their natural state ; when it was 

 deemed more satisfactory to ascertain, however imperfectly, the 

 composition of a mineral, than to measure the angles of its crys- 

 talline forms, to determine its action upon light, or obtain from 

 experiment its hardness and specific gravity. 



Fortunately for mineralogy, chemists have advanced so far in 

 their inquiries, that, besides obtaining new compounds, and dis- 

 covering new modes of producing them, they may now devote 

 their attention to a more accurate examination of those which 

 they have known long ago to exist. Professor MITSCHERLICH'S 

 doctrine of isomorphous bodies, is one of the most interesting 

 consequences already deduced from these comparisons. The 

 path entered upon by the artificial production of Pyroxene, of 



