Mineralogy and Geology. 281 



ing obtained the specimen as represented. Mr. L. had no suspicion of 

 its being any thing more than silver, which was known to be found with 

 the gold. The place at which he obtained it, was in Rutherford Co., 

 near the line of the new county of McDowell. I would have sent you 

 his certificate, but I had no doubt that other specimens would be found. 

 In fact, almost every miner to whom I described it said, he had seen 

 just such specimens, but they had supposed them to be fragments of 

 steel or iron that had been broken from the edges of the mining tools."* 



3. Oxyd of Cobalt with the Brown Hematite Ore of Chester Ridge, 

 Pa., (Proc. Amer. Phil. Soc, Jan., 1846, iv, 239.)— Dr. Boyi exhibi- 

 ted to the Society a specimen of brown hematite ore from Chester 

 Ridge, three-fourths of a mile west of Chester furnace, Huntingdon 

 County, Pa., containing a small quantity of oxyd of cobalt, — the sur- 

 face of the ore is in some places covered with a thin film of oxyd of 

 cobalt. It also contains a moderate proportion of manganese. 



The ore was dissolved in chlorohydric acid, the solution neutralized 

 by ammonia, and then the iron precipiiated by boiling after previous 

 dilution with water. The oxyd of cobalt which remained in the solu- 

 tion with the manganese, was discovered both by its reaction in the 

 moist way, and by the blue bead it yielded with salt of phosphorus. 



* Bhmuthic Gold.— In the letter from which the above is extracted, was forward- 

 ed to me a few grains, of which the largest weighed only 0907 gr., of an alloy of 

 bismuth and gold, to which faint traces of mercury were adhering. Concerning 

 their origin, Mr. C. observes, " They were brought to me by a friend, Mr. Willis, 

 under the impression that they might be platinum They were mix^l with the 

 gold of several days work, and I assisted him in picking them out from a parcel 



that he brought to the bank in this place. They are evidently not grains of pla- 

 tinum." 



In structure they are hackly, or sub-fibrous. Hardness = 2-5. . .3-0. Gr. 

 «"44 • . . 12-9. Color that of palladium. Malleable, but when thinned out under 

 'he hammer it becomes brittle. Scarcely acted upon by nitric acid, or by hydro- 

 chloric alone ; but in the two, slowly dissolves save traces of a heavy white pre- 

 cipitate. Heated before the blowpipe on charcoal, it melts as soon as touched by 

 'he flame into a globule which gives off a white smoke, at the same time coloring 

 •ne supp 0rl of a bright yellow while the charcoal remains hot, but turning white, 

 * h en cold. If allowed to cool, the globule crystallizes beautifully, w.th a coarse- 

 '7 indented surface, and has its color changed from grayish white to a distinct 

 f den yellow tinge. By continuing the heat, the globule gradually wastes away 

 J 1 Jew than half its original bulk, crystallizes less distinctly, grows less fusible, 

 °d finally it puts on the appearance of pure gold. 



Fbe foregoing notice is introduced here in the form of a note, on account of the 

 "»picion entertained that the substance may prove to be only a product of ihe mi- 

 ly process of separating his gold by means of amalgamation, instead of being a 

 \ rue mineral production. Dr. Gibbon, the Superintendent of the U. S. Branch 

 J"« »t Charlotte, N. C, whose opinion on the subject I solicited, assures me, that 

 b "tntl, has repeatedlv been detected in several of the gold districts of the south- 

 *» states, and that he' thinks the substance in question is probably a natural pro- 

 ol "• . Mr " Clingman also observes in reference to the same point, • It is my 

 J mum that the grains sent to you were in their natural state. I have seen gold 

 JJ»ed so as to he blackened by a film of lead supposed to be obtained from the 

 J< Cl ".v, but it was only superficial and could easily be rubbed off; bu the grams 

 *"< you were of a steel grey color, and when fractured were seen to have the 

 fj»e color within as externally- Some of them indeed had a color more nearly 



"nmg to yellowish, and yielded slightly before breaking.' 



*>scohd SerieS) Vol. IV, No. 11— Sept., 1847. 36 



