RE-EXAMINATION OP AMERICAN MINERALS. 165 



of sulphate, carbonate, and yellow molybdate of lead; but these 

 last were small, and bear no comparison to those described, 



It was hoped that something might be learned concerning 

 the formation of the minerals of this vein; but the difficulties 

 and uncertainty attendant upon the study of questions of this 

 kind make it prudent to postpone any views that might be 

 suggested. It may, however, be well to remark that in open- 

 ing the vein, and descending from the surface for the first 

 thirty feet, the phosphate of lead was very abundant, with 

 some galena and carbonate. A little lower down the phos- 

 phate was less and the carbonate more abundant. Wulfenite 

 and anglesite began to appear at one hundred and twenty feet. 

 The phosphate and carbonate still continued with the galena, 

 with fine large crystals of anglesite and considerable wulfenite. 

 At one hundred and eighty feet phosphate very much dimin- 

 ished; carbonate and sulphate in fine crystals. Arsenate was 

 found here. At two hundred and forty feet blende, calamine, 

 and fluor-spar appear with considerable dolomite and but little 

 phosphate of lead, galena forming almost the whole lead-ore. 

 Anglesite is found, but in smaller crystals. These observations 

 may hereafter lead to some conclusions as to the manner of the 

 formation of these minerals, but at present I prefer dismissing 

 the subject without further remarks. 



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