520 G. P. Merrill — Minor Constituents of Meteorites. 



Cobalt (Co) 0-098$ 



Copper (Cu) 0*008 



Chromium' (Cr) 0*029 



Carbon (C) 0*017 



Manganese (Mn) __ 0*015 



Iron (Fe) 21*270 



100*5988 



None of the rarer elements, other than those noted, were 

 found. 



(9) Meteoric stone. MacKinney, Collin County, Texas. 

 Referred to by Brezina* and relegated to his Cs type, charac- 

 terized by colorless chondrules firmly imbedded in a dark gray 

 to black ground. The mineral composition and structure are 

 given but no analyses. Dr. Whitfield found the stone to 

 consist of : 



Troilite (FeS) 6*26 



Schreibersite 0*58 



Metal 5*70 



Chromite 0*11 



Silicate minerals 87*35 



100*00 



The silicate portion yielded : 



Silica (SiOJ 43*30$ 



Alumina (Al 2 OJ 15-18 



Ferrous oxide (FeO) 8-45 



Lime (CaO) , 1*88 



Magnesia (MgO) 30*48 



Manganous oxide (MnO) 0*25 



Nickel oxide (NiO) 0*5 1 



100*05$ 

 The metallic portion yielded : 



Iron (by difference) _ _ 85*84$ 



Cobalt ' 0-92 



Copper _. __ 0*08 



Nickel __. _ ._ 13*16 



100 



Barium, strontium and zirconium, in addition to the other 

 rarer elements, were looked for but no traces discovered. 



(10) Meteoric stone. Holbrook, Arizona. Described by 

 Merrill.f A gray chondritic stone, very fresh, having fallen 



*Ann. K. K. Hofmus., x, p. 252, 1895 (96). 



f Smithsonian Miscellaneous Collection, lx, No. 9, pp. 1-4, 1912. 



