312 M. Ebelmen on 



ments of very old date, in which, by the melting of different 

 substances, crystalline products have been obtained com- 

 posed of different ingredients promiscuously intermingled ; it 

 has been corroborated since by the examination of scoriae, &c. 

 of smelting-houses, in which crystalline matters have been 

 found identical with some of the natural substances occur- 

 ring in the above mentioned rocks. Finally, it has been con- 

 firmed by direct experiments, in which, by fusion, certain 

 minerals have been fonned at pleasure, and many analogous 

 substances. However, certain problems remained to be 

 solved, as, fortunately for our successors, will always conti- 

 nue to be the case. Here, for example, matters more or less 

 analogous to the minerals formed in our smelting houses 

 (usines), such as we have directly formed hj uniting the com- 

 posing ingredients in suitable proportions, have all hitherto 

 been fusible substances ; but it very often happens in nature 

 that such matters are accompanied by others which resist the 

 most violent fires of our furnaces, and frequently also the 

 latter envelope the former ; thus quartz, corundum, spinel, 

 and cymophane, &c., all infusible substances, ai'e found along 

 with others which melt more or less readily. It thence fol- 

 lows that we can attain to no certainty as to the origin of 

 these matters ; and if, by analogy, we admit that they have 

 likewise been produced by fusion, we must suppose tempera- 

 tures which we cannot produce but by means of blowpipes of 

 detonating gas, with which only trifling attempts at crystal- 

 lisation can be attempted. Consequently nothing positive 

 could be ascertained I'especting these bodies. 



These doubts appear to have occupied ]M. Ebelmen's mind, 

 and led him to the idea, from which important consequences 

 may be derived. He conceived that it was not merely the 

 fusion of substances at a temperature more or less elevated 

 that might determine the combination of different elements, 

 and the crystallisation of composite forms, but that it must 

 likewise frequently happen that there will be real solutions 

 of these substances, even of such as are infusible, in certain 

 substances in fusion, just as there is a solution of different 

 salts in water or other liquids ; and that, consequently, 

 ci'ystallisations ought to be formed either by the evaporation 



