1881 .J 



477 



[Chance. 



appeared to be graj^ copper was pulverized as a whole, and analyzed with 

 the follow in 2; result : 



0.0530 



0.16T3 



98.55 



If the gray substance be considered homogeneous then its molecular 

 ratio will be 



ES : r^S' = 3.1 : 1 



But gray copper has the ratio of 4 : 1. If the bismuth sulphide be now 

 eliminated with the corresponding positive sulphide in the Alaskaite ratio 

 of 1 : 1, then we get for the ratio of the rest 



RS : SbjSs = 3.86 : 1 

 that is nearly the gray copper ratio. 



It is made even more probable that such a mixture be here in existence, 

 by qualitative tests -upon a large specimen, weighing several kilograms of 

 the massive gray mineral. These tests indicated very vaiying percentages, 

 by the intensity of bismuth reaction from different points of the piece. 



It is a matter of remark from a genetic point of view, that we find in 

 this vein nests of Alaskaite quite free from the gray copper, while the 

 latter seems to be mixed generally with the former in other places when- 

 ever it predominates. 



T7ie Auriferous Gravels of jVoj'th Carolina. By H. 31. Chance, M.D. 

 (Read before the American Philosopliical Society, July 15, ISSl.) 



The belt of auriferous gravel stretching in an almost unbroken line from 

 the New England States to Alabama, is broadest in North Carolina, 

 where it has also been more productive in the past, and promises 

 greater results in the future than in any other State through which it 

 passes. 



Yet notwithstanding the flattering prospects apparently presented by 

 these gold fields, the companies organized to work them have rarely at- 



