METEOKITES OF NORTH AMERICA. 207 



This piece also has the peculiar dark-brown crust of meteoric iron in small portions, while upon the prominent 

 parts it has long been rubbed or cracked off. 



On both sections the finer threads of white metals can be seen, showing the structure of the Widmannstatten figures. 



Fortunately the section running most distinctly according to the form lies almost exactly parallel to the plane of 

 an octahedron. 



The bands intersecting one another at angles of 120° and 60°, according to Partsch, run in perfect parallelism 

 over the entire etched surface, having a width of about one-half line with triangular and rhomboid interspaces between 

 the inclosing films of schreibersite. They manifest quite unmistakably an enduring crystalline activity through a 

 period for which we have as yet no measure. Neither the cleavage nor the laminated structure parallel to the cubic 

 faces is seen as in the Ilauptmansdorf iron, nor the crystal damask sheen, as in the Bohumilitz iron, comes to view here, 

 but the true Widmannstatten figures, as seen in the Elbogen, Agram, and Durango irons, very similar also to the structure 

 of the great mass of iron of 1,635 pounds weight from Red River (Louisiana or Texas). The zigzag lines which appear 

 in the figure are disruptions of the crystalline mass, parallel to the octahedrons. 



The specific gravity at 12° (C?) was 7.362 in the case of the larger fragments. It would probably be higher in 

 case of the smaller fragments, since the cracks present (on the exterior) indicate possible separations in the interior. 



Madelung 8 made the following analysis : 



Fe Ni Co P Insoluble 



90.764 7.607 0.889 trace 0.053 =99.313 



G=7.741. 



Brezina 8 in 1885 stated: 



The laminae measure 0.8 mm. in width and are finely flecked. 



Meunier 9 states : 



Etching produces a perfectly normal etching design where the three elements of the caillite appear with their 

 characteristics most perfectly defined. 



Brezina 10 described sections in the Vienna collection as follows: 



A section lengthwise almost through the entire mass of a specimen in the Vienna Museum shows a zone of alteration 

 0.5-3 mm. wide along the natural exterior and is entirely covered with a system of octahedral cracks, which follow the 

 course of the laminae, in consequence of which frequent zigzags from one lamina to another occur along the principal 

 laminae, giving the appearance of the ramifications of lightning flashes. Another piece shows pressure figures 2-3 cm. 

 in size and the slightly altered fusion crust with elongated outcroppings of troilite with daubreeilite bands. On a third 

 slice the zone of alteration, which measures in this case 1-1.5 mm. in width is not glistening as usual, but shows a different 

 orientation of luster without other change. The laminae are of the same dull appearance as the fields, which are mostly 

 filled with repetitions of the laminae. 



The meteorite is distributed. The largest piece (10 pounds) is in the museum of the Academy 

 of Science of St. Louis. 



BIBLIOGRAPHY. 



1. 1858: "Choteau presented a mass of meteoric iron, 35 pounds weight, found in Nebraska Territory, about 20 miles 



from Fort Pierre." Trans. St. Louis Acad. Sci., vol. 1, 1857-1860, p. 307. 



2. 1860: Holmes. Trans. St. Louis Acad. Sci., vol. 1, pp. 711-712, pi. 21. (Illustration of entire mass, and analysis 



by Prout.) 



3. 1860: Shepahd. Notices of several American meteorites. — I: Nebraska iron. Amer. Journ. Sci., 2d ser., vol. 



30, pp. 204-205. 



4. 1860: Haidinger. Einige neuere Nachrichten fiber Meteoriten, namentlich die von Bokkeveld, New Concord, 



Trenzano, die Meteoreisen von Nebrasca, von Brazos, von Oregon. Sitzber. Wien. Akad., Bd. 41, p. 571. 



5. 1860: Haidinger. Notiz fiber das Meteoreisen von Nebraska. Sitzber. Wien. Akad., Bd .42, pp. 744-746. (Illus- 



tration of etching, and analysis by Prout.) 



6. 1862: Madelung. Ueber das Vorkommen des gediegenen Arsens in der Natur nebst den Analysen einigerneueren 



Meteoriten. — Das Meteoreisen von Nebraska. Dissert. Gottingen, No. ?, pp. 39-40. 



7. 1861-1865: von Reichenbach. No. 15, pp. 110, 124, and 128; No. 16, p. 261; No. 17, pp. 266 and 272; No. 18, 



p. 487; No. 19, p. 154; and No. 25, p. 437. 



8. 1885: Brezina. Wiener Sammlung, pp. 213, 214, and 234. 



9. 1893: Meunier. Revision des fers meteoriques, pp. 52 and 56. 

 10. 1895: Brezina. Wiener Sammlung, p. 277. 



