366 Ores of Manganese. 
[Articles of Foreign Literature and Science Extracted and Translated by 
P iscom. | 
rofessor Grisco 
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 
stone. e 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 kt It is penetrated with a 
ella e, 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, . 
a 
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