258 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



plessite, which is distinguished from the usual compact, dark variety only by reason of the somewhat coarse grain and 

 greater abundance of glistening scales (or grains?). Under stronger magnification the latter stand out distinctly upon 

 a black, dull groundmass. Brezina's error is accounted for by the fact that the glistening scales are sometimes arranged 

 in rows. Aside from a few small schreibersite grains no minor constituents were observed. 



All that is at present known of this meteorite (28 grams) is in the Vienna collection. 



BIBLIOGRAPHY. 



1. 1892: WARD. Illustrated Descriptive Catalogue (Rochester, New York), p. 15. 



2. 1895: BUEZINA. Wiener Sammlung, p. 272. 



3. 1905: COHEN. Meteoritenkunde, Heft 3, p. 388. 



KENDALL COUNTY. 

 Texas. 



Latitude 29 39' N., longitude 98 25' W. 

 Iron. Granular hexahedrite, Hk. Brecciated hexahedrite (Hb), of Brezina; Kendallite (type 



23), of Meunier. 

 Found ?; described 1887. 

 Weight, 20f kgs. (45.9 Ibs.). 



The history and characters of this meteorite are given in a summary by Cohen as follows : 



Kendall County was first mentioned by Brezina ' in 1887, who gave its weight at 20| kg., and compared the iron 

 provisionally to Zacatecas. In 1893, he 2 referred it to his breccialike hexahedrites, stating that the size of the indi- 

 vidual distinctly separated grains varied from a few millimeters to 3 to 4 cm. In 1895, he 4 noted the presence of tro- 

 ilite grains, mostly angular and of a maximum diameter of 4 cm., which were penetrated by tongues of iron or a gran- 

 ular iron band. In a few grains of iron he noted peculiar skeletons produced by etching, which were taken for troilite. 

 Small iron grains were also mentioned as occasionally surrounding a large one in the form of a wreath. 



According to Meunier,* Kendall County is distinguished from all other irons by its fragmentary and heterogeneous 

 structure. A few fragments give by etching, he states, regular figures, but most of them show only a sort of mohair 

 sheen. A black, carbonaceous substance occurs, sometimes in granular particles, sometimes as a matrix of the 

 " breccia. " The specific gravity varied from 6.94 to 7.10. 



In 1895, Moissan V examined Kendall County for diamond and graphite. After dissolving with dilute hydro- 

 chloric acid and treating the residue with aqua regia there remained a black, amorphous substance, mixed with numer- 

 ous transparent little grains which disappeared after repeated heating with sulphuric acid and hydrofluoric acid at 

 varying temperatures. The remainder appeared as amorphous carbon, which was with difficulty attacked by nitric 

 acid and potassium chlorate, but left no trace of carbonic acid. A part of the transparent grains were regarded as 

 sapphire; the other portion, of a bottle-green transparent character, was not definitely determined. 



Cohen's 8 study gave the following: 



After etching, the nickel iron is decomposed into grains whose diameter varies from 0.5 mm. to 3 cm. ; although a 

 measurement of 1 cm. is the exception. Moreover, different portions of the meteorite vary somewhat. In many places, 

 the larger part of the cracks dividing the grains are filled with an intimate mixture of schreibersite with a graphitic 

 substance, occasionally also with one of the two metals alone. A close examination showed that not graphite but 

 amorphous carbon was present, as Moissan had already proved. By dissolving the nickel iron in dilute hydrochloric 

 acid the above combination is left in thin plates 1 sq. cm. in size. In other places lumps of carbon-schreibersite as 

 much as 3 cm. in size occur between the grains of nickel iron, which run into the former in the shape of small, elon- 

 gated tongues. After weak etching most of the grains show only Neumann lines, while a smaller portion (and indeed 

 only the larger grains) takes on a distinct, uniform, and peculiarly dull luster. It is produced by numerous etching 

 pits, which lie so closely crowded together that it is only under high magnification that they can be discerned or dis- 

 tinguished from one another. After stronger etching, the number of grains with etching pits is increased. Further, 

 there appears, besides the sharply defined crevices which divide the grains, and within the former, still another 

 system of irregular cracks, which under the microscope show as delicate veins; however, they do not, like the prin- 

 cipal crevices, each define an individual, and may be a kind of fracture phenomenon. Finally there are a few grains 

 which are rich in black, dull inclusions. 



In other portions of the Kendall County iron which contain much less secondary material, the carbon-schreiber- 

 site veins between the grains are wanting. Only a small portion of the latter show the Neumann etching lines; the 

 greater part become uneven after etching and show under the microscope numerous black, dull inclusions (above 

 referred to), which can be studied more exactly here. They are sometimes grains, sometimes rods; and as the latter 

 intersect one another at right angles, they give rise to a knitted appearance. This accordingly may be that forma- 

 tion which Brezina called "a peculiar skeleton" structure, and which he regarded as of only occasional occurrence. 

 According to the appearance and the behavior after etching, a carbonaceous substance appears to be present; evidence 

 to the same effect is found in the high percentage of carbon (1.62 per cent), although a specimen was used for analysis 

 which contained no visible carbon. 



