June 5, 1S96.] 



SCIENCE. 



831 



brilliant lustre, with powder and streak 

 chocolate brown. It is brittle, with frac- 

 ture conchoidal and hardness between 2 

 and 3 ; specific gravity, 1.07. The min- 

 eral is, like many others of the asphalt se- 

 ries, undoubtedly composed of a number of 

 hydrocarbon compounds. Its position, from 

 a physical standpoint, is at one end of the 

 hydrocarbon series, petroleum, naphtha, 

 and the gaseous substances being at the 

 other, with the viscous malthas between. 



Deposits of this hydrocarbon compound 

 are, so far as present known, confined to 

 the Uncompahgre Indian Reservation and 

 its immediate vicinity in eastern Utah. 

 The allied compound, Grahamite, occurs in 

 "West Virginia, and again in the Huasteca 

 in the northwest part of the State of Vera 

 Cruz, Mexico. Albertite, another near 

 relation, has long been known in New 

 Brunswick. It is quite possible also that 

 many of the solid asphalts of other areas 

 will, upon a more extended knowledge of 

 their composition, be found to belong to one 

 or another of these species. 



The largest deposits of Uintaite are lo- 

 cated along the Colorado-Utah line, 30 to 

 50 miles north of the Rio Grande Western 

 Railway ; others of workable width lie 40 

 to 50 miles west near the western edge of 

 the Uncompahgre Reserve. 



The deposits lie in the Uinta Basin, origi- 

 nally a structural basin, bordered by the 

 Uinta Mountains and the Yampa Plateau 

 on the north, the Wasatch Range on the 

 west, the White River Plateau on the east, 

 and the Roan or Book Plateau on the south. 

 Erosion has greatlj^ modified the surface ap- 

 pearance of the basin, the streams having 

 cut canons in some instances 3,000 feet in 

 ■depth. 



The geological formations of the basin 

 proper are of Eocene Tertiary age and in- 

 clude the Laramie, Wasatch, Green River, 

 Bridger, Washakie (?) and Uinta, the 

 whole constituting a grand terrane of sand- 



stones, shales and thin inconspicuous lime- 

 stones. 



The Uintaite is confined to no particular 

 formation. It occurs as veins filling vertical 

 cracks from \ inch to 18 ft. wide and from a 

 fev hundred feet to 5 or 10 miles in length. 

 They have a general northwest-southeast 

 trend. They cut shales, sandstones and 

 limestones alike, and no disj)lacement of 

 the strata on either side of these cracks has 

 ever been observed. The veins themselves, 

 however, are faulted from 2 or 3 inches to 2 

 ft. Lateral cracks of wafer thinness are, in 

 some instances, given oif from the main 

 vein, all filled with the asphaltic substance. 

 The strata for a foot or two from the vein are 

 often strongly impregnated with the Uinta- 

 ite. Horses of the wall rock also occur, 

 completely enveloped in Uintaite. The es- 

 timated contents of the veins to a depth of 

 1000 ft. is 20,000,000 tons. 



Dr. Wm. C. Day (Journ. Franklin In- 

 stitute, Sept., '95) has found Uintaite to 

 consist of 56.46 % volatile matter, which is 

 nearly or quite all condensable, 43.43 % 

 fixed residue and 0.10 % ash ; and that its 

 percentage composition is • 



Carbon 88.30 



Hydrogen 9.96 



Sulphur 1.32 



Ash 0.10 



Oxygen and Nitrogen unde- 

 termined 0.32 



100.00 



He speaks of it as comprising a number 

 of radically difierent series of hydrocarbons, 

 among which the parafiin series is one, and 

 probably also the naphthene. No aromatic 

 hydrocarbon appears to be present, or at 

 most only in small quantity. 



Uintaite is used in the manufacture of 

 the cheaper black varnishes ($1.25 and 

 down) and of japans, being especially prized 

 on account of its elastic properties. It is in 

 common use throughout the United States. 



