4 Professor Jacob Berzelius on Meteoric Stones. 



wards dissolving the silica in boiling carbonate of soda. There 

 remain, then, 



2. Silicates ofmagnexia, lime, oxide of iron, oxide of man- 

 gancsc, alumina, potash ami soda, which are not decomposed 

 by acids, and in which the silica contains twice the oxygen of 

 the bases. Probably there occur mixtures of several of these 

 silicates which I could not separate. We might thus deduce an 



augite like / (.#*, and a leucite-like mineral, in which lime 



c J 

 and magnesia replace, in the first term, a part of the potash and 



soda: N V 2 + 3 A S* The cause of the augite not being co- 



* ' 



loured like the terrestrial, is the same as in the case of the me- 



teoric olivine. 



3. Chromate of Iron. It is contained in both species of me- 

 teoric stones, and in both in equal quantity ; it is never awaut- 

 ing, and is the source of the chrome in meteoric stones. It 

 can be obtained undecomposed by decomposing the non-magne- 

 tic part of the meteoric stone in hydro-fluoric acid, which is then 

 expelled by sulphuric acid ; and by afterwards separating the 

 sulphate of lime and other sulphates by boiling water, when the 

 chromate of iron remains in the form of a blackish-brown pow- 

 der. It is the cause of the greyish-black colour of meteoric 

 stones, when regarded in the mass. 



4. Oxide of Tin. It is mixed with chromate of iron. We 

 can be convinced of its presence by fusing the latter with sul- 

 phate of potash, then treating the mass with water, and passing 

 sulphureted hydrogen through the solution, by which sulphuret 

 of tin is precipitated. It contains traces of copper. 



5. Magnetic iron probably does not occur in all. We recog- 

 nise it by its property of dissolving in muriatic acid with a yel- 

 low colour, and without evolution of hydrogen. 



6. Sulphuret of iron is contained in all. It was impossible 

 for me to separate a portion for examination. Every thing 

 seems to indicate that it contains one atom of each of its con- 

 stituent parts. We cannot imagine an excess of sulphur in a 

 mass where an excess of iron every where predominates. A 

 portion of the sulphuret of iron follows the magnet at the same 

 time with the iron; another portion remains in the powder, 



