Geology of Massachusetts. 47 
iron and earthy matter. Hence it differs but little from some varieties 
of anthracite. It seems indeed to be the form in which carbon occurs 
in the oldest of the rocks. In Massachusetts it exists in gneiss, at 
the most important locality, which is in Sturbridge. It there occurs 
in a bed, varying in width from an inch to about two feet, and trace- 
able along the surface, nearly one hundred rods. A number of years 
ago this bed was opened; and several tons of the graphite obtained. 
It was then abandoned ; but within a few years the exploration has 
been recommenced, and already more than a hundred tons have been 
obtained. In some places the excavation is six or seven feet deep. 
The quality of the graphite is excellent; and would not suffer by com- 
parison, with almost any in the world. ‘l’o what extent it may be ob- 
tained, it is not possible at present to determine. The fact, that the 
bed descends, almost perpendicularly, into the earth, is rather unfavor- 
able to the miner. Yet, as itis found upon elevated ground, the 
mine can be conveniently drained by lateral cuts or adits to a consid- 
erable depth; and probably the exploration may be_ profitably con- 
tinued for a long time with little machinery. 
Graphite is employed for pencils, crucibles, lubricating machinery, 
&c. It occurs at several other localities in Massachusetts, besides that 
in Sturbridge, but not in large quantities, exeept perhaps in Hinsdale. 
It is said that a good bed of it has been opened in New Hampshire. 
A substitute for Emery. 
No real emery has yet been found in Massachusetts; but a rock 
composed of garnet and anthophyllite or augite, occurs in North 
Brookfield, which is employed as a substitute for that mineral, and 
it is said to answer well. ‘The powder of the garnet, although much 
inferior in hardness to real emery, is indeed sometimes called in com- 
merce, red emery. ‘The rock in Brookfield is abundant, and may 
prove valuable. 
Mineral Waters. 
No mineral springs of much notoriety are found in the state, al- 
though chalybeate springs are very common, and are useful in 
cutaneous and some other complaints. Nearly all these springs 
rise in low ground. containing bog ore. The Hopkinton spring is 
of this description, and is probably more resorted to than any 
other in the state. This contains, among other ingredients, car- 
bonic acid and carbonate of lime and iron. The spring in Brook- 
field is similarly situated, and contains some magnesia and soda, as 
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