258 ANNUAL OF SCIENTIFIC DISCOVERT. 



the shales as potroloum, after their iiplieaval, fillincr crevices per- 

 hajjs fonued Ity tl»at uplieaval, and to liave harileuod in time into 

 its jiresent Ibnn. 



Annhjsis of t/ii.t Bitumen hy Aug. A. TTayes, M.T). — The physi- 

 cal characters uftliis mineral coinuH-t it with tlie variety ofcannel 

 coal called Albertite; a fact which g^ives great interest to the 

 discovery, apart from economical considerations. 



in chinjical comjjosition, relation to heat and solvents, it differs 

 from Aliiertite remarkably, and falls within the class of true i)itu- 

 mens, of which it is an important member, well charactei'ized. 



When the cannel coal of New Brunswick was discovered and 

 descril)ed, ;jeolo<;ists and mint-raloiri'^ts were unwilling to class it 

 with known coals of the cannd kind, on account of its general 

 resemblance to some known bitumens. Jet, from the tertiary 

 formation, seemed to be its neari'st relative but so strong was the 

 impression of its physical characters, that it received a distinctive 

 name, l)y which it is n(»w known. Meantime, observations have 

 multiplied over a larger surlace, and in this country two discov- 

 eries have been made which render the reception of a new fact 

 less difficult. 



1. The discovery, some seven years since, of the bitumen of 

 Ritchie County, Va. This is a true bitumen, fdling a chasm la 

 the sandstones of the coal formation, without shales or clay, and 

 the deposit is extensive above the surface, and continuous more 

 than one hundred feet below it. 



The physical characters of this bitumen do not differ from those 

 of bituminous coal of the prismatic form. Geologists and mineral- 

 ogists have carefull}' examined and pronounced it coal. In j^lace, 

 it is a bitumen, and all its chemical characters and composition 

 fix it firmly in the class of bitumens. 



Here we have a bitumen with the external characters of coal, 

 so distinct as to place it among the more common coals ou in- 

 spection. 



2. Prof. Denton has made known a most valuable deposit of 

 oil-producing bitumen, whose external characters ai'e exactly 

 those of the so-called All)ei-tite, Avliile the mineral in place fills a 

 fracture in the rocks, Avithout shales or clay. Either in its bed, or 

 in the laboratory, it is a true bitumen, differing from Albertite aa 

 bitumens dilfer from coal. 



These discoveries seem to diminish the apparent objections 

 urged to receiving the Albertite as a cannel coal, in the wa}^ of 

 presenting a coal on the one hand which is bitumen, and an Al- 

 bertite on the other, which is also a bitumen. They show, too, 

 the important aid which may be derived from chemical inquiries, 

 connected with geological observations. 



In physical characters, this mineral resembles the Albertite of 

 New Brunswick. The same variety of fracture is observed, and 

 hand siaecimens side by side hardly differ. Specific gravity varies 

 from 1.055 to 1.075 ; electric by friction. 



When heated, it loses 0.33 per cent, of moisture, and at 340° 

 Fahr. begins to emit vapors of hydrocarbons, soon melts and in- 

 tumesces. It expands about five times its volume in decompos- 

 ing, and affords a porous brilliant coke. 



