112 ORIGIN OF PENNSYLVANIA PETROLEU^E. TFeb. 5, 



are, where we now find them, distillates. In making this declara- 

 tion I do not wish to be understood as calling in question the cor- 

 rectness of either the observations or opinions of those who have 

 reached different conclusions. 



Perhaps fifty years from now our ghosts may sit here with our 

 grandchildren and hear them dogmatize concerning the origin of 

 bitumen. For myself, the longer I study the subject and the wider 

 my experience becomes, the less I am prepared to assert that any 

 formula is capable of universal application. I would therefore 

 suggest, that, as we now find them, bitumens are in some instances 

 Still where they were originally produced by a process of decompo- 

 sition of animal remains, that is at present being illustrated on a 

 small scale in the shallow bays of the Red Sea. Further, that 

 other deposits contain primary distillates from the vegetable and 

 animal remains enclosed in geological formations that have been 

 invaded by heat, steam and pressure in past periods of the earth's 

 history ; and finally, that in some instances, as we now know them, 

 bitumens have been transferred and stored by a secondary invasion 

 of bituminous deposits by heat, steam and pressure. The details 

 of these various movements await for their expression a vast amount 

 of chemical and geological research by those who are to come 

 after us. 



A SUGGESTION AS TO THE ORIGIN OF PENNSYL- 

 VANIA PETROLEUM. 



BY DAVID T. DAY, 



{Read February 5, IS 97.) 



The three general classes of theories as to the origin of petro- 

 leum are so well known as to call for no especial description. I 

 refer to (i) the inorganic origin by the action of water on metallic 

 carbides ; (2) by the slow decomposition of vegetable remains with 

 insufficient supply of air, with or without simultaneous production 

 of coal ; and (3) the distillation of the fatty portion of anima 

 organisms under pressure, in accordance with the discoveries gener- 

 ally credited to Engler. 



It is pleasant, however, to recall attention to the fact, which has 

 frequently been lost sight of, that Warren and Storer first distilled 

 petroleum from animal fats years before ; that is by the distillation 



