Crystallized Minerals by Heat. 131 



pxygen of the lime was equal to the oxygen of the magnesia; 

 and in another experiment, he melted the same elements in 

 $uch a proportion, that the oxygen of the magnesia was 

 double the oxygen of the lime. The results of both were 

 pyroxenes, the counterparts of which we find in nature; the 

 first is the ordinary pyroxene, the other is one of those from 

 Finland, analysed by Mr. Nordenskidld. The crystals of 

 silicate of manganese, which I had never seen before, obtain- 

 ed by M. Berthier in fusing carbonate of manganese with 

 silica, are particularly remarkable ; they are very well pro- 

 nounced, and possess exactly the form of the silicate of iron 

 described above, and of peridot. 



3. Having the appearance of Mica. — There are some va- 

 rieties among the old scoriae, found in the vicinity of Gar- 

 penberg castle in Sweden, which present absolutely the same 

 characters as mica. They produce an uniform mass, consisting 

 of lamella; of two or three lines diameter, semitransparent and 

 splendent. In the drusy cavities there ai'e transparent six- 

 sided tabular crystals. In regard to its composition, which 

 I ascertained by analysis, it resembles the black Siberian mica 

 analysed by Klaproth. 



Mica from Garpenberg. Mica from Siberia. 



Inferences from the preceding observations in regard to 

 Geology. — The artificial production of minerals by fusion 

 puts beyond the slightest doubt, the idea of our primitive 

 mountains having been originally in a state of igneous fusion. 

 This state gives a satisfactory explanation of the form of the 

 earth, of the increase of temperature at greater depths, of hot 

 springs, and many other phenomena. At that time, during 

 this high degree of temperature, the water of the sea must 

 have formed an elastic fluid round the globe, according to the 

 experiments of M. Cagnard dc la Tour. 



