1897.] PETROLEU.AE IX THE CAVITIES OF FOSSILS. 121 



ation, yielding hydrogen and carbon together with small quantities 

 of unsaturated hydrocarbons, notably acetylene. On the other 

 hand, petroleum has been shown by the important researches of 

 Mabery to contain a series of hydrocarbons which are usually char- 

 acteristic of reactions at high temperatures. The fact that such 

 hydrocarbons occur in petroleum, whether in small or large quanti- 

 ties, is of very great interest and should have due weight in the 

 selection of any hypothesis proposed to account for its origin. At 

 present this fact can hardly be considered to furnish evidence either 

 for or against the views of Mendeleeff in regard to the origin of 

 natural gas. 



ON THE OCCURRENCE OF PETROLEUM IN THE 

 CAVITIES OF FOSSILS. 



BY FRANCIS C. PHILLIPS. 



{Bead February 5, IS 97.) 



In the study of geological facts bearing upon the history of petro- 

 leum, much interest has been aroused during recent times by the 

 discovery of petroleum enclosures in the cavities of fossils in lime- 

 stone rocks. Such occurrences, observed in many places, and in 

 deposits of different geological age, from the Silurian onward, have 

 been regarded as furnishing proof that the genesis of oil is to be 

 attributed to chemical changes taking place in the tissues of the origi- 

 nal organism of the fossil, and therefore as strengthening a com- 

 monly accepted belief that the hydrocarbons contained in the rocks 

 have originated from animal remains stored in the sediments which 

 afterwards became consolidated into rock. 



The relationship suggested between the petroleum and the fossils 

 is all the more interesting and important since the oil-bearing sand 

 rocks of the Devonian age do not, as a rule, contain remains of 

 animal life, and furnish no satisfactory clues as to the origin of oil 

 and gas. As tending to confirm the evidence which such facts have 

 been supposed to furnish, numerous instances have been cited where 

 hydrocarbons are apparently produced from remains of more recent 

 animal life, as in coral reefs and in the accumulations of organic 

 remains buried under marine or fluviatile sediments. In certain 



