298 ANNUAL OF SCIENTIFIC DISCOVERY. 



NEW METALLIFEROUS DEPOSITS. 



DR. JACKSON has communicated to the Boston Society of Natural 

 History the fact, that the plumbaginous mica slates of Vermont con- 

 tain a considerable portion of tin diffused through their mass, in a state 

 of combination not yet determined. The specimens examined were 

 from two localities, and yielded a considerable quantity of an alloy of 

 tin and iron when fused in a crucible lined with lampblack. Speci- 

 mens of the rock were exhibited by Dr. Jackson, with globules of the 

 metal extracted from it. This discovery is an important one, as it 

 points to the probable occurrence of tin ores in districts where they 

 never were suspected to exist. For if an extensive rock formation is 

 filled with tin in some state of combination, veins of the oxide or sul- 

 phuret cannot fail to exist somewhere. Pieces of plumbaginous slate, 

 so full of graphite as to prove valuable as plumbago, have been recent- 

 ly analyzed in Dr. Jackson's laboratory, and yielded malleable grains 

 of an alloy of tin and iron. 



Dr. C. T. Jackson has discovered, in Labrador felspar from 

 Franklin, N. J., small black crystals, which contain oxide of cerium, 

 similar to that obtained from ores found in Sweden. 



A communication in SilHman''s Journal, for March, from Dr. F. B. 

 Hough, states that he has discovered sulphuret of nickel at the Ster- 

 ling Mine, in Antwerp, Jefferson Co., N. Y. " It occurs mostly in 

 radiating tufts of exceedingly minute and slender crystals of a brass- 

 yellow color, and very brilliant lustre, which, when highly magnified, 

 present the appearance of flattened hexagonal prisms with striated 

 faces, the striae being parallel with the principal faces of the prism. 

 It occurs in geode-like cavities of the iron ore, which are lined with 

 crystallizations of spathic and specular iron, quartz, calcite, cacoxene, 

 and sulphuret of iron ; from among these the tufts proceed, attached 

 generally to the spathic iron, more rarely to the crystals of iron." It 

 is by no means abundant. Minute crystals are found penetrating and 

 traversing the spathic iron. 



Platinum has recently been discovered in several localities in the 

 Alps, by M. Gueymard. It occurs in very minute quantities associ- 

 ated with gray copper ore, in a gangue of delomites, quartz, gneiss, 

 and limestones. Some indications of rhodium have also been noticed 

 in specimens obtained from the platinum localities. It is found in 

 three different localities. Comptes Rendus, Dec. 31, 1849. 



At the Boston Natural History Society, April 17, Mr. Tesche- 

 macher exhibited some grains of platinum from the washings on the 

 Feather River, California, with the gold from which he had picked 

 them out, several grains still remaining mixed therewith. These 

 platinum grains from California appeared to resemble those from 

 South America, the Russian platinum being less rounded and flattened 

 by attrition. 



LAKE SUPERIOR IRON DEPOSITS. 



THE following mention is made of the iron deposits near Lake Su- 



