THE OIL-FIELDS OF EASTERN CANADA. — ELLS. 605 



to waste muck time or capital in an attempt to obtain oil in 

 quantity from an area where the rock formations are much dis- 

 turbed. In several such cases small quantities of petroleum 

 have indeed been obtained, sufficiefnt for the time to lead the 

 explorer to invest additional sums of money, though the final 

 outcome, as might have been expected, has generally been, 

 disastrous. 



On the hypothesis now generally accepted, oils have 

 originated from the decomposition of animal or vegetable 

 organisms which have been buried during the process of rock 

 formation precisely as we see going along our sea shore at the 

 present day, where shells, seaweeds, fish, etc., are buried by the 

 accession of sands or other materials which are moved by tidal 

 currents or by wind action. 



These decomposed organisms, with their resulting carbon 

 contents, were supposed by Dr. T. S. Hunt to be the actual 

 source from which petroleum was derived, and the resulting 

 oil to form a part of the formation in which they are deposited, 

 preferably in limestone, since their remains were easily recog- 

 'nized and were often observed to be highly charged with oily 

 matter in the several strata encountered. He, therefore, con- 

 te^nded that petrolemn originated from the primary decom- 

 position of organic matter and pertained to the stratum in 

 which the organisms were first laid down. Another school, 

 however, contended that the original source of the potroleimi 

 was in some lower stratum, and that the oil resulting from the 

 decomposition of organic matter, as well as the accompanying 

 gases, rose or percolated through underlying sediments till 

 they encountered a non-pervious layer, bei'ng assisted in this 

 upward movement by the action of percolating waters at a 

 greater underlying depth. 



On this latter theory the oils of the Petrolia district, which 

 may be taken as an example of the general principle, have 

 originated at some lower horizon than that in which they are 



