118 PECKHAM — THE GENESIS OF BITUMENS. [April 1, 



11. In Prof. James Hall's celebrated Introduction to The Palce- 

 ontology of New ^ork, he shows that the earliest paleozoic sedi- 

 ments were deposited in a current that moved from southeast to 

 northwest. Later the current moved diagonally across them from 

 northeast to southwest. These later currents represent a vast inter- 

 val of time, during which material accumulated to a depth of tens 

 of thousands of feet of coarse sediments to the northeast in Canada, 

 and growing finer diminished to the southwest in the Mississippi 

 valley to a few thousands of feet. If metamorphic action is due to 

 the accumulation of sediments, whereby the isothermal lines of the 

 earth's crust rise to meet the increased pressure, by consequence of 

 which sediments are brought into a state of igneo-aqueous fusion, 

 it is not difficult to explain why, at a period in the earth's history, 

 when the condition of the earth's crust, the ocean and the atmos- 

 phere, all contributed to maintain a high temperature, the strata as 

 we pass from the southwest in the Mississippi valley towards the 

 northeast should present, at the surface, increasingly the effects of 

 heat.^ 



12. Let us now turn to Technology and see what the experience 

 of more than half a century can teach us in relation to this ques- 

 tion of the origin of Bitumen. Soon after 1830, Reichenbach in 

 Germany,-^ Selligue in France and Gregory in Scotland, all worked 

 upon, the destructive distillation of pyroschists, wood, coal, peat 

 and petroleum. They all discovered paraffine, and what is sugges- 

 tive, they all propounded the idea that bitumens are distillates. 

 They established the fact that pyroschists, wood, coal, etc., when 

 destructively distilled yield paraffine and the oils found in petro- 

 leum. Selligue established quite a valuable industry in France, 

 using as his raw material the schists of Autun. About 1850, the 

 Scotch paraffine-oil industry arose. The raw material was a shale, 

 called Boghead mineral, that was well known to contain fossil 

 fishes. The distillate of this mineral closely resembled petroleum, 

 and when petroleum was discovered in the United States in com- 

 mercial quantities, the refineries on the Atlantic coast, that had 

 been importing the Boghead mineral, commenced to work petro- 

 leum with slight changes in their processes. At the same time, the 



1 Nat. Hist, of A\ V., " PaLxontology," iii, 45-60. 



"^ Jour, fur Chem. u. F/iys., von Schweiger-Seidel, 1830, lix, 436. Trans. Roy. 

 Soc. of Edjnb.yxm, 12^. Rep. of Fat. Invev., n. s., iv, 109. Jour.des Con- 

 naisances Usuelle^ Dec, 1834, p. 285. Dingier, Ivi, 40. 



