508 



Scientific Geology. 



crystals terminated by tetraedral pyramids. The sulphate of lead oc- 

 curs in small plates on the galena. The phosphate of lead exists in 

 spherical light green masses. 



The vein in the south part of Southampton is said to have a gangue 

 of quartz containing galena, and to be not more than a foot wide. I 

 have not visited it. 



About a mile northeasterly from the adit in Southampton, a vein of 

 quartz, mostly radiated, several feet wide, traverses mica slate chiefly, 

 and contains blende and galena ; the former in much the greatest 

 quantity. The blende here, as well at all the veins in the vicinity, is 

 foliated, rarely in distinct crystals, and of a honey yellow color. 



The vein in West Hampton, near the locality of argentine, is very 

 large, at least 10 feet wide: though I could not ascertain its true width. 

 It is composed entirely of radiated and crystalized quartz, surround- 

 ing small masses of some other reck, probably mica slate, the whole 

 mass having a brecciated appearance. Galena, the only ore that has 

 been found here, is very sparingly disseminated. I could not ascer- 

 tain whether this vein is in granite or mica slate; both of which rocks 

 occur in the vicinity. 



The veins in Williamsburgh, according to Mr Nash, occur in 

 granite and mica slate, and the gangue is quartz. Only one of them, 

 however,has been discovered in the rock,their existence being inferred 

 from the loose blocks strewed over the surface. In at least one of 

 these veins, the oxide of mangenese occurs, along with galena. Py- 

 ritous copper exists there also, in small quantity : and I found foliated 

 blende. This ore appears to have a strong tendency to decomposi- 

 tion, and often the cavity that contained it, is filled with a dull red 

 powder whose true nature I have not yet ascertained. But it is cer- 

 tainly not the oxide of lead, as Mr. Nash has stated in the 12th vol- 

 ume of the American Journal of Science! 



The three veins in Whately have all a gangue of quartz, generally 

 radiated. The most easterly one, according to Mr. Nash, contains 

 oxide of manganese as well as galena. The most northerly one is 

 six feet wide and lies chiefly in granite. It contains blende as well 

 as galena. The two other veins described by Mr. Nash I have tried 

 in vain to find. 



According to the Messrs. Danas, muriate of copper has been found 

 in a rolled mass of granite in Woburn. 



It is said, also, that specular oxide of iron occurs in Mendon, 

 and in Cumberland, R. Island, in granite. 



