38 



GEOLOGY OF LA SALLE COUNTY. 



But how, says one, do you account for the 

 formation of coal? 



We believe that a laro-e part of our coal was 

 once petroleum or pitch, lakes of oil or swamps of 

 pitch like the Pitch lake of Trinidad, and that on 

 to or into these were carried trunks of trees, 

 leaves, fruits, plants of many kinds and much sedi- 

 ment, and that then all were buried beneath thick 

 beds of cla}^ and sand, and that this process by 

 chang-es of level was repeated more than once on 

 the same ground. Hence the name viineral coal 

 is a very apppropriate one. But where did the 

 petroleum come from ? We believe it to be formed 

 in the recesses of the earth by the direct combina- 

 tion of carbon and hydroo-en in several proportions, 

 forming- several distinct substances, which are min- 

 g-led as we obtain them, but are easily separated 

 by distillation. It was once an arg'ument aofainst 

 this view that we could not cause these elements 

 to unite and form petroleum, but we believe this 

 has been accomplished by Mendelietf, and thus our 

 inability to form it is no longer, if it ever was, a 

 valid objection to our theory. There is no evidence 

 that the source of these oils is animal and veg*- 

 e table remains. Rocks, which are a vast burying-- 

 g-round of extinct tribes of marine life, the monu- 

 ment of races that have ceased to be, whose every 

 particle has at some distant past been instinct with 

 life, show^ not a trace of oil or anything- resembling- 

 it. This is just as true of vegfetable as of animal 

 remains, the necropoli of one being- as destitute of 

 oil as the other. 



Natural g-as is also a product not of slow dis- 

 tillation, but of the natural combination of the two 

 constituent g-ases within the earth, and its forma- 



