Analysis of the New-Jersey Ores of Zine. 323 
come, between the oxid of zinc and the oxid of manganese, 
did not depend upon the intervention of any undiscover- 
ed substances, I dissolved pure oxid of zinc with the tenth 
part of its weight of oxid of manganese, equally pure, and 
heated the solution by the process deseribed under No. 2. 
{ obtained, as in the case of the American mineral, an ace- 
tous solution, with which the alkaline carbonates formed a 
precipitate, that became, in consequence of calcination, of 
a dirty yellow, and contained manganese. 
Ul. The black zinciferous mineral, the Frankliniic. 
This mineral is composed of the oxid of iron, the oxid of 
manganese and the oxid of zinc. The association of these 
three oxids has never been before observed, and there is 
‘ron whose powder is black. The specific gravity is 4,87. 
{tis searcely affected by the muriatic acid in the cold; 
ut, by means of this acid, we can separate the carbonate of 
lime and the manganesian oxid of zinc, with which it is al- 
most always mixed, and thus we can obtain it perfectly pure. 
It dissolves very easily in hot muriatic acid, without effer- 
‘vescence but with a slight smell of chlorine. The analysis 
