20 MEMOIRS NATIONAL ACADEMY OF SCIENCES. [vol.xiv. 



The silicate portion yielded: 



Per cent. 

 Silica (SiOj) 43.30 



Alumina (AI2O3) 15- 18 



Ferrous oxide ( FeO) 8. 45 



Liine(CaO) 1.88 



Magnesia (MgO) 30.48 



Manganous oxide (MnO) .2.5 



Nickel oxide (NiO) 51 



100. 05 

 The metallic portion yielded: 



Per cent. 



Iron (by difference) 85. 84 



Cobalt 92 



Copper .08 



Nickel 13.16 



100.00 



Barium, strontium and zirconium, in addition to the other rarer elements, were looked 

 for but no traces discovered. 



(16) Meteoric stone, Gray CJiondrite (Cg). — Monroe, Cabarrus County, N. C. This stone 

 has been briefly described by several writers and subjected to at least one previous chemical 

 analysis. The first examination was made by C. U. Shepard " who relied for his mineralogical 

 determinations upon the results of chemical analyses, thin sections at that date not bemg avail- 

 able. Wadsworth mentioned it briefly in his Lithological Studies, but added little excepting to 

 justly remark that "judging from its general character Shepard's analysis is incorrect and it is 

 hoped a new one may be made." Wiilfing in his catalogue places the stone in Brezina's group, 

 Cga, that is, with stones consisting of a tuff-like mass with variously colored chondrules firmly 

 embedded in the ground. It remains to be stated that the chondrules are in part of olivine and 

 in part of pyroxene, both varieties occurring in porphyritic or in barred or radiating forms. Two 

 varieties of pyroxene are recognizable, the one obscurely twinned and monoclinic — the kUno- 

 enstatite variety — and the other occurring frequently in large peUucid forms and orthorhombic 

 in crystallization. Metallic iron and iron sulphides with their oxidation products complete the 

 list of recognizable minerals. The wide discrepancies between the analyses of Shepard and 

 Whitfield can be accounted for on the supposition that the material utilized by the first named 

 was not representative and his methods imperfect. 



Shepard's analysis: 



Per cent. 



SiUca (SiOj) 56. 168 



Ferrous oxide (FeO) 18. 108 



Magnesia (MgO) 10. 406 



Alumina (AI2O3) 1.797 



Nickel-iron with traces of chromium 6. 326 



Magnetic pyrite 3.807 



Lime, soda, potash, and loss 3. 394 



100. 006 

 Whitfield's results as follows: 



Per cent. 



SiUca(Si02) 36. 7l' 



Alumina (AI2O3) : 3.59 



Chromic oxide (C-jOs) Trace- 

 Ferrous oxide (FeO ) 14. 80 



Manganous oxide (MnO) 23 



Nickel and cobalt oxides (NiOCoO) 46 



lime(CaO) 2.27 



Magnesia (MgO) 24. 54, 



Iron (Fe) 12. 58 



Nickel(Ni) 87^ Metal 13.54 



Cobalt (Co) 09 



Amer. Journ. Sci., vol. 10, 1850, p. 127. 



Per cent. 

 Silicates.. 82.60 



