448 REPORT OF NATIONAL MUSEUM, 1899. 



ring in shrinkage fissures whose course is N. 76 to 80 E. in Carbon- 

 iferous shales and sandstones, on a branch of Hughes River, Ritchie 

 County, West Virginia. It is completely soluble in chloroform and 

 carbon disulphide, nearly so in turpentine, and partially so in naphtha 

 and benzine, but not at all in alcohol. Melts somewhat imperfectly, 

 beginning to smoke and soften like coking coal at a temperature of 

 about 400 F. (Specimen No. 59924, U.S.N.M.) 



As occurring in the vein the material shows four distinct, though 

 somewhat irregular, divisional planes, having a general parallelism 

 with the walls. Next to the walls the structure of the mineral is 

 coarsely granular, with an irregularly cuboidal jointed cleavage, very 

 lustrous on the cleavage surfaces, that in immediate contact with the 

 walls usually adhering thereto very tenaciously, as if fused fast to the 

 granular sandstone. (Specimen No. 59941, U.S.N.M. A "horse" or 

 fragment of sandstone from the vein, showing adhering grahamite.) 



Next to these two outside layers, which are very irregular and from 2 to 3 inches or 

 more in thickness, is found, on each side of the vein, a layer averaging from 15 to 16 

 inches in thickness, which is composed of a variety highly columnar in structure and 

 very lustrous in fracture, the columns oeing long and at this place at right angles to 

 the walls. Finally, in the center of the vein, varying in thickness, but averaging 

 about 18 inches, is a mass differing greatly in aspect from the rest, being more com- 

 pact and massive, much less lustrous in fracture, and with the columnar structure 

 much less developed, in places not at all. The fracture and luster of this portion of 

 the vein are clearly resinoid in character. 



The general aspect of the mass, as well as all the results of a minute examination 

 of the accompanying phenomena, lead irresistibly to the conclusion that we have 

 here a fissure which has been filled by an exudation, in a pasty condition, of a resinoid 

 substance derived from or formed by some metamorphosis of unknown fossil matter 

 contained in deep-seated strata intersected by the fissure or dike. 



The density of a mass of the mineral was found to be 1.145. The horizontal extent 

 of visible outcrop actually measured by me was 530 fathoms, thinned out at east end 

 to 30 inches and at west end to 8 inches; but as these points were at least 70 to 80 

 fathoms vertically higher than the bottom of the ravine, the width (averaging about 

 50 inches) at the latter depth points to a rapid widening of the fissure in descent.'- 



J. P. Kimball has described 2 a deposit of similar material on the 

 west bank of the Capadero River in the Huasteca, VeraCruz, Mexico. 

 The country rock is a fossiliferous Tertiary shale overlaid by con- 

 glomerate. 



The grahamite occurs in a fissure some 34 inches in thickness 

 terminating in an "overflow" some 6 feet in maximum thickness, 

 thinning away at the edges, but the full extent of which wu.s not 

 determined. The evidence showed that the fissure had been tilled 

 by material oozing up from below and spreading out upon the 

 surface prior to the deposition of the overlying gravel. The strike 



1 Proceedings of the American Association for the Advancement of Science, XVIII, 

 1869, pp. 125-128. 



2 American Journal of Science, XII, 1876, p. 277. 



