140 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



the same neighborhood, which unfortunately was worked up to within 1 pound's weight. This iron is especially 

 noteworthy because of its great similarity with the Arva iron described by Haidinger. At least this similarity was 

 striking in the specimen found in the Royal Berlin Museum, as well as in a small fragment of 28 grams weight which 

 was obtained from Sowerby in London. On the surface and to some extent in the body of the mass it is changed into 

 pyrosiderite, which crumbles easily, in which frequently are found leaves of schreibersite, sometimes quite large and 

 of a yellowish-white color with a metallic luster and flexible in texture, quite similar to that of the Arva iron. After 

 etching a small, well-polished surface on this iron, a very noticeable marking of fine parallel lines appears, which is 

 visible to the naked eye in the sunshine by the peculiar luster of the surface. 



The small fragments of the Cosby Creek iron which served as the materials for this analysis were given me by Mr. 

 Sowerby on the occasion of the former's last visit to London. They were all very much oxidized on the exterior. 



The analysis gave the following results: 



Fe Ni Co P Cu and Sn Mn Graphite Quartz S 



91.635 5.846 0.809 0.195 0.219 0.092 0.798 0.079 ? =99.673 



Portion insoluble in hydrochloric acid, 3.21, consisting of schreibersite, graphite, and quartz. 



Bergemann a also made an analysis as follows : 



I undertook an analysis of this meteoric iron, which had already been examined by Shepard, as I possessed a 

 broken fragment of*4 grams weight, which showed very distinctly the lamellae that are insoluble in muriatic acid. I 

 recorded the results of this analysis because they differ from those of Shepard. The specific gravity I found to be 

 7.257. The insoluble residue weighed 0.083 grams, equal to 2.075 per cent. No hydrogen sulphide was developed in 

 the process of dissolving the material, and no metal was precipitated by hydrogen sulphide. 



The residue mostly consisted of a black dust in which yellowish particles of a metallic luster were present in con- 

 siderable quantity in the form of small scales and were easily removed with the magnet. The black amorphous powder 

 weighed 0.0077 grams, burned readily when heated on platinum foil, and left a trace of a residue consisting of iron 

 oxide. The particles removed by the magnet and freed from all carbon by washing possessed a gray color shading into 

 brown and a specific gravity of 6.99. 



The following figures were yielded by the analysis: 



Soluble. Insol. Res. 



Fe 90.096 1.802 



Ni 6.521 0.183 



Co 0. 332 



P 0.021 0.068 



C... 0.175 



99. 198 



Reichenbach 7 made numerous observations upon the meteorite, the most important of 

 which are as follows. In Study XII, page 458, he says: 



If we consider * * * the North American Sevier, Caryfort, and Cosby, as well as Tejupilco and Bata, we find 

 in all magnetic pyrites as large as walnuts, of a smooth rounded form, or in the form of sections of a cone. I also 

 possess pieces of graphite of the size of walnuts from the Cosby meteorite which fall out upon crumbling this loose 

 iron mass. 



On page 460 he says: 



I obtained from a large specimen of the Sevier meteorite a piece of pure iron sulphide as large as half a finger. It 

 fell out in the process of cutting and had the form of a belemnite (arrow stone). In a cross section, at right angles with 

 the axis, it showed distinct, concentric rings and the longitudinal section showed how these lay one over the other in 

 the form of layers and scales along the entire length of the body. Such a case occurs seldom enough to make a sketch 

 worth while (which is accordingly given in the text). It is very easy to see from this how the iron sulphide is formed 

 and how it is arranged in crystalline layers around its core. The hatching shows the different directions of the foliation 

 of each layer of pyrites. Only upon the first thin layer around the core is the foliation indistinct. But the entire cone 

 was an indisputable product of free crystallization proceeding intermittently. 



In Study XV, page 111, he says: 



If we compare further the coarser meteoric irons we see the Trias recurring, especially in Cosby, the light gray 

 beam-like iron, the reddish fawn-colored band iron, and the grayish plessite, although all much modified. The beam 

 iron indeed shows its lines or hatching distinctly but coarser. On the other hand, this is no longer formed in such 

 regular bars, no longer developed in the beautiful rectilinear and parallel intersections, but is sprawled out in irregular, 

 puffy, and nodular masses in which the eye is able only with difficulty to perceive, in the larger formations a longitudinal 

 extension in contrast with breadth and thickness. There is little of the isabel-yellow colored band iron, it is so thin 

 that it must be sought for with the glass. The plessite is brighter, approximates the beam iron in color, remains always 

 without hatching, and is by this single characteristic to be distinguished from the latter. 



