76 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



i 



Fourth time. — Nickel iron and pyrrhotine, cast upon the surface of the chondrites and injected into their fissures. 



Fifth time. — Black minerals, arranged in very fine lines, arising from local reheating, without fusion and generally 

 in consequence of mechanical action. 



A similar complication, 'which is found still more prominent in many other types of cosmic rocks, furnishes a very 

 strong argument. 



Brezina 8 describes the meteorite as follows: 



Bluff is not very distinctly crystalline, but stands between Ckb and Cgb, approximating more nearly to the first. 

 The special peculiarity is the yellowish-brown to orange-red weathered crust, elsewhere found in olivine-gabbro, which 

 in this meteorite attains a thickness of 2 to 3 mm! A large section of the stone, through the entire mass, measuring 53 

 by 30 cm., frequently shows a blackish infiltration from the crust in a dark green groundmass, to the depth of 2 or 3 

 mm., which penetrates the entire stone diagonally and obliquely, and from which blackish, sack-like apophyses, 2 

 to 4 cm. in width, branch out into the groundmass. The color of the fresh broken surface varies from greenish-gray, 

 through light gray, to pistachio-green and greenish-brown. Grains of iron up to 1 cm. in size are frequently present, 

 sometimes consisting of a grain enclosed in troilite, sometimes of loose, closely packed, roundish grains. 



The black veins previously referred to were described in detail by Howell. 2 He says: 



The black veins observed at several points on the surface are found to extend entirely through the mass and are 

 arranged mainly in two sets, in each of which the veins are approximately parallel, the two sets crossing each other at 

 an angle of about 45°. The systematic arrangement of the veins, which may be only accidental, is shown in a cross 

 section through the center. As the planes of the veins are cut at nearly right angles by the sections, they show on each 

 of them in approximately the Bame positions. This is particularly the case with the narrow vein shown at the base of 

 the section. Although only a mere line, it is uniform throughout, and is seen in exactly the same position on all of the 

 sections; therefore we have already revealed the plane of this vein, 15 by 4 inches, with no indications of petering out. 



The irregular thick vein also maintains a nearly uniform appearance throughout the 4 inches of thickness. 



The sections also reveal a number of fissures or cracks formed subsequent to veins, and doubtless at the time of 

 the fall. 'A dark clouding for the most part surrounds these fissures, the darkest parts being farthest from the fissure 

 and terminated in some cases by a dark line similar to the veins. As not all of the fissures are surrounded by this 

 dark shading, and as some of the clouded spots contain no fissures, it argues that the coloration can not be the effect of 

 decomposition induced by the cracks, particularly as there is no apparent effect of decomposition extending in from 

 the surface of the stone. The clouding is perhaps older than the cracks, and formed lines of weakness which the 

 cracks followed. 



Whitfield and Merrill ' also described a black vein as traversing the section which they 

 examined. They stated that it had the form of an irregular fissure extending 60 mm. and vary- 

 ing in width from a mere line to 2 rum. The vein material was more compact and darker in 

 color than the main mass of the meteorite, but proved on analysis to differ but little hi compo- 

 sition except in the absence of lime. The analysis gave the following: 



Si0 2 - 38. 96 



Fe 2.39 



FeO 22.98 



A1 2 3 1. 89 



MgO 27.52 



Ni and Co 3. 26 



S 0.26 



97.26 

 Specific gravity, 3.585. 



The meteorite is distributed among collections. 



BIBLIOGRAPHY. 



1. 1888: Whitfield and Merrill. The Fayette County, Texas, Meteorite. Amer. Journ. Sci., 3d ser., vol. 36, pp. 



113-119. (Analysis and illustration.) 



2. 1888: Howell. Science. Vol. 11, pp. 55 and 266. 



3. 1888: Meunier. Determination lithologique de la meteorite de Fayette County, Texas. Comptes Rendus, Tome 



107, p. 1016-1018. 



4. 1889: v. Hauer. Ann. K. K. Naturhist Hofmus. Wien, Bd. 4 (Not.), p. 64 and Bd. 5, (Not.), 1890, p. 62. 



5. 1893: Brezina. Ueber neuere Meteoriten (Nurnberg), p. 162. 



6. 1893: Newton. Lines of structure in the Winnebago County Meteorites and in other Meteorites. Amer. Journ. 



Sci., 3d ser., vol. 45, pp. 152-153 and 355. 



7. 1894: Cohen. Meteoritenkunde, pp. 61, 202, 298, and 316. 



8. 1895: Brezina. Wiener Sammlung, p. 261. 



