Geology of Massachusetts. 61 
on one hand, and under the river, on the other hand, into sandstone. 
The gangue is sulphate of barytes and toadstone, and the ores are 
the green carbonate and pytitous copper. Actual eee alone 
can determine whether these veins might be profitably wor 
On the mosi southern of the smai} islands, in the middle ”: Tur- 
ner’s Falls, has been found pyritous copper, of a rich quality, 
and in considerable quantity. Indeed, several varieties at the sand- 
stone rocks in the vicinity, appear to be considerably impregnated 
with copper. 
Pyritous copper is associated with iron, in a vein, in greenstone, 
at Woburn; but not, probably, 1 in a sufficient quantity to be worth 
mining. At several places in Cumberland, R. I., where excavations 
were formerly made, are found gray weide of copper, and pyritous 
copper with the green and blue carbonates. 
Zine. 
The sulphuret of this mineral occurs, as has already been noti- 
ced, in several of the lead veins in Hampshire County, and in some 
of them in sufficient quantity, no doubt, to be wrought with advantage, 
should these veins be ever opened. ‘Those in Southampton, Hattield 
and Leverett, abound most in this ore. It is useful in the manufac- 
ture of brass and white vitriol. 
Manganese. 
In a metallic state this mineral is of no use ; and indeed, it is reduced 
to that state with great difficulty. But in the state of oxide, it is 
extensively employed, both to remove color from glass and to im- 
colors; also in painting porcelain and glazing pottery, and 
still more extensively within a few years, in the manufacture of the 
chloride of lime, now so generlly used in bleaching and for disin- 
ection. 
At least two ores of manganese abound in the western part of 
Massachusetts and on the borders of New Hampshire. It has been 
already remarked, that more or less of the gray oxide exists in the 
iron beds of Berkshire and Bennington, Vt. In the vicinity of Con- 
necticut River, however, or rather on the eastern slope o oosac 
mountain, distinct veins and beds of manganese are found. 
In Plainfield. 
Beds of the oxide of manganese occur in two places in this town— 
one a mile west of the center, and the other near the south-west cor- 
