390 S. F. Peckham — Origin of Bitumens. 



be included the idea that polymerization has played any 

 important part in the formation of natural bitumens ; an idea 

 that has lately been so ably discussed by Prof. Henry Wurtz.* 



The organic origin of bitumens may therefore at present be 

 accepted as practically undisputed. The question then recurs, 

 are bitumens distillates or are they indigenous in the rock 

 formations in which they are found — in other words, have 

 they been produced in situ ? 



Twelve years ago, when preparing the essay on the Origin 

 of Bitumens which forms a part of my report to the 10th 

 Census of the United States, I wrote, that the derivation of 

 bitumens had not in my judgment been uniform. That 

 opinion took form in my own mind as a growth which was 

 determined by many years of thought and a wide experience. 

 This experience began with a very careful study of all the phe- 

 nomena attending the occurrence of bitumen in Southern 

 California during 1865-6, and the preparation of a report 

 upon the same for the Geological Survey of California. I 

 left California fully convinced that petroleum was of animal 

 origin and formed in situ. Soon after I had returned to the 

 Atlantic coast, I met Dr. J. S. Newberry in his office in New 

 York and with Baron v. Koschkull held a long conversation 

 upon Russian and American petroleum and incidentally upon 

 their origin. Dr. Newberry then for the first time awakened 

 my interest in the distillation hypothesis and based his argu- 

 ment upon the results that had been obtained in technical 

 operations in Ohio in the distillation of coals and shales prior 

 to the discovery of petroleum in Pennsylvania. The argu- 

 ment is all to be found in his celebrated paper on " The Rock 

 Oils of Ohio";f but no one could resist the persuasive elo- 

 quence with which he developed the idea of that vast Sargossa 

 sea that, gathered in the Devonian ocean, produced the 

 Devonian shales from which the petroleum of eastern Ohio 

 and western Pennsylvania was distilled. His speculation 

 stopped at this point, with the idea that the oils were distil- 

 lates. 



Later, 1 was for a time in frequent intercourse with Cyrus 

 M. Warren, whom we all remember with so much affection. 

 He described to me in great detail the experiments he had 

 made by saponifying menhaden oil with lime and distilling 

 the lime soap. The amount employed was several tons, and 

 he obtained the distillate in such quantity that a part was 

 refined into illuminating oil, and the remainder was fraction- 

 ated in Warren's apparatus. In fact, the experiment was 

 made for technical purposes : but the results are only of 



* Engineering, various dates. 



f Ohio Agricultural Report, 1859, p. 605. 



