62 Geology of Massachusetts. 
ner of the town; and both in talcose slate. Two ores are associ- 
ated at both these places, viz. the common gray or black oxide and 
the silicious oxide; the former investing the latter as a black crust, 
and most probably proceeding from its decomposition ; while the 
latter, when newly broken, is of a delicate rose red. I suspect the 
silicious oxide predominates at these places; and from these beds, 
probably came by diluvial action, those numerous rounded masses 
of silicious oxide in the vicinity of Cummington meeting-house ; al- 
though a deep valley intervenes and the distance is three or four 
miles. An -attempt was made, some years ago, to explore one of 
these beds, under the impression that the ore was iron. But how 
extensive either of them is, it is difficult to determine, as each seems 
to consist of a number of small beds—or rather the ore is inter- 
laminated with the slate. The occurrence of so much silicious ox- 
ide at these localities, is very interesting to the mineralogist, because 
this ore is so rare in Europe. 
In Conway. 
A distinct vein of the black oxide of manganese several feet wide 
occurs in the southeast part of this town, the gangue being quartz. 
It has not been explored at all; nor is the manganese ore very 
abundant at the surface. I do not doubt however, that this ore may 
be found here in large quantities. 
In Hinsdale, N. H. 
An extensive bed or vein of the black, and silicious oxides 
of manganese have been found in this town. It appears near the 
top. of a hill and the adjacent rocks are not visible. The ore strong- 
ly resembles that from Plainfield. 
In Winchester, N. H. 
Between one and two miles east of the center village in this town, 
may be seen large quantities of the black and red oxides of this me- 
tal of the same character asin Hinsdale. ‘These localities have, 
as yet, attracted no attention except from a few mineralogists. 
My information and specimens were furnished me by Mr. John L. 
Alexander of Winchester. 
Tin. 
I am able to say with perfect confidence that this interesting me- 
tal exists in Massachusetts; but can add little more. I found 
