3GS Ores of Manganese. 



[Articles of Foreign Literature and Science Extracted and Translated by 

 Professor Griscom.] 



1. Ores of Manganese. — Berthier has analysed nine va- 

 rieties of the ores of Manganese, viz. three of the Peroxide, 

 one of the Hydrate, three of the Barytic variety, and two of 

 the silicate. The following table exhibits the results of this 

 able chemist. The Peroxide from Crettnich, near Saar- 

 bruck, is that which is abundantly used at Paris and in the 

 north of France. It is confusedly crystallized in needles. 

 The Peroxide from the isle of Timor, is amorphous, com- 

 pact, of a pure black grey, with a slight metallic lustre, 

 and is intimately mixed with carbonate of lime. The Per- 

 oxide from Calveron is much of the same character. The 

 Hydrate is from Lavelline, department of Vosges ; it is 

 amorphous, cellular, of a deep metallic black, its powder 

 of a deep brown, its fracture commonly granular, and 

 sometimes lamellar. Its numerous cavities are filled with 

 argil and oxide of iron. 



The Barytic manganese forms a thick and extensive bank 

 at Romaniche, in the department of Saone et Loire. There 

 are two varieties called by the inhabitants grey stone and 

 burnt stone. The former is much employed at Lyons and 

 in the south of France, and even at Paris. The other Ba- 

 rytic species, from Perigueux, has the same aspect as the 

 compact kind from Romaniche. The silicate from Saint 

 Marcel, Piedmont, is of a greyish metalloidal black, com- 

 pact, with considerable lustre. It is penetrated with a 

 lamellar stony substance, white and hard, the nature of 

 which is not known. The silicate from Pesillo, Piedmont, 

 is compact, of a slightly greyish black, but almost without 

 metallic lustre. It is intimately mixed with magnesian 

 carbonate of lime, white and crystalline, whence its frac- 

 ture is slightly lamellar. 



