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crystalline nodules of epidote and black tourmaline, sometimes 

 beautifully crystallized. The principal shaft is said to have been 

 one hundred feet deep; and the mine was drained by a long adit 

 which commences near the base of the hill, not far from the 

 canal. A considerable sum has been expended without success, 

 in opening this mine. 



Interpreting all the appearances connected with the nature and 

 the mode of distribution of the ore, it would seem to be so difiused 

 throughout the altered shale, as to preclude its being ever profit- 

 ably wrought. 



At the base of the trap ridge north of Somerville, occurs the 

 Bridgewater Copper Mine, once worked to some extent, but with 

 a serious waste of capital. Several facts respecting the position 

 of the ore in the midst of the altered shale, at some little distance 

 from the dike of trap, have been already mentioned. It was found 

 here principally in the moderately altered rock, near to which it 

 is excessively baked by proximity to the igneous rock. The ore 

 is pronounced to have been very rich, consisting of a considerable 

 proportion of massive red oxide of copper. There was also 

 found some native copper. The chief variety of ore, however, 

 was the usual green carbonate, mingled occasionally with green 

 phosphate, and some of the green silicate of copper. 



This mine has been for a number of years closed up. Judging 

 from the character of the rubbish outside of the mine, which 

 gives a tolerably correct conception of the mode in which the 

 ore occurs, we infer that it is here accompanied by very little 

 true gangue or vein stuff, being sometimes in the form of thin 

 partial injections, but much more frequently existing in a dis- 

 seminated state among the altered shale and sandstone. 



The Flemington Copper Mine, the only one recently wrought 

 to any extent, being open to inspection, gives an opportunity of 

 ascertaining accurately the usual mode of position of the ore. 

 In this mine the appearances are almost conclusive, as regards 

 the absence of a true vein, and corroborate strongly the opinion 

 already advanced, that the chief portion of the ore has pene- 

 trated the minute crevices of the impregnated rock, rather by 

 a species of sublimation, than by intrusion or injection in the 

 fluid state. 



There seems to be a belt of metalliferous rock of very variable 



