442 EEPORT OF NATIONAL MUSEUM, 1899. 



and stated to 1)0 iUndal and at a high temperature in the center.' Thi,^ 

 is quite erroneous and misleading. 



The crude material has the following composition and physical 

 characteristics:' 



Specific gravity, 1.28; hardness at 70° F., 2.6 to 3 of Dana's scale: 

 color, chocolate brown; composition: 



Bitumen 39. 83 



Earthy matter _ 33. 99 



Vegetable matter 9. 31 



Water 16. 87 



100. 00 



In western Kentucky asphalt exudes from the ground in the forn 

 of "tar springs," and occurs also disseminated through sandstones anc 

 limestones of sub-Carboniferous age. (Specimen No. 68345, U.S.N.M. 

 Frequentl}', as in the dolomite luiderlying Chicago, Illinois, the bitu 

 minous matter is so diffused throughout the rock as to give it on expo 

 sure a brownish-black appearance, and cause it to exhale an odoi 

 of petroleum appreciable for some distance. (Specimen No. 62789 

 U.S.N.M.) In the Dead Sea bituminous masses of considerable siz( 

 have in times past risen like islands to the surface of the water anc 

 furnished thus the material used by the ancients in pitching the wall: 

 of buildings and rendering vessels water-tight. The ancient name o 

 this body of water was Lake Asphaltites^ and from it our word asphal 

 is derived. These illustrations are sufficient to indicate the numerou; 

 conditions under which the su])stance occurs. The material is world 

 wide in its geographic distribution and equally cosmopolitan in it 

 geological range, being found in gneissi(^ rocks of presumaT)ly Archfeai 

 age in Sweden, and in rocks of all intermediate horizons down to lat' 

 Tertiary. 



Some 10 miles east of the city of Habana, Cuba, is a deposit o 

 asphalt described ^ as occupying an irregular branching tissure in i 

 soft clay rock, with eruptive rocks, diorites, and euphotides in the nea 

 vicinity. The asphalt, described as "Coal" in the paper referred to 

 lies in parallel horizontal layers of from 1 to 4 inches in thicknes 

 across the vein, the lamina being somewhat deflected near the walls 

 as if pressed by the sides or walls. The deposit is regarded as havin; 

 originated as an open fissure terminating upward in a wedge-lik 

 form and into which was subsequently injected from below the carbo 

 naceous matter. The asphalt itself was described as of a jet-blacl 



^See Mineral Resources of the United States, 1883-84, p. 937; also Dana's Syster 

 of Mineralogy, 1892, p. 1018; and especially S. F. Peckham's paper on the Pitc 

 Lake of Trinidad, American Journal of Science, July, 1895, p. 33. 



^Transactions of the American Institute of Mining Engineers, XVII, 1889, p. 363. 



* London and Edinl)urgh Philosophical Magazine and Journal of S(;ience, X, 183'i 

 p. 161. 



