Origin of Carbonaceous Shales. 



363 





1 



2 



3 



4 



5 



6 



Moisture, 



1.10 



0.86 



0.75 



0.54 





1.10 



Inorganic matter, 



87.10 



84.60 



78.29 



83.17 



79.36 



76.00 



Volatile combustible do. 



6.90 



8.36 



14.12 



8.26 



12.60 



11.30 



Fixed Carbon, 



4.90 



6.18 



6.84 



8.03 



8.04 



11.60 





100.00 



100.00 



100.00 



100.00 



100.00 



100.00 



No 1. Cleveland Shale, Carboniferous, Cleveland, Ohio, (Wormley. ) 



No. 2. Huron Shale, Monroeville, Ohio, - - - (Wormley. ) 



No. 3. Hudson River Shale, Savannah, Ills., - - (Chandler.) 



No. 4. Utica Shale, Dubuque, loM'a, - - - (Chandler.) 



No. 5. " " Collingwood, Canada, - - (Hunt.) 



No. 6. G-enesee Shale, Bozanquet, " - - - (Hunt.) 



The relations of the bituminous shales to the cannel coals are 

 very intimate ; indeed they may be said to be but different 

 phases of the same substance, as they have been formed in simi- 

 lar conditions, and shade into each other by insensible grada- 

 tions. I have suggested a theory to explain the origin of cannel 

 coal, which supposes it to be composed of the completely ma- 

 cerated parenchymatous tissue of plants, accumulated in lagoons 

 or water-basins in the coal-marshes. The water of such lagoons 

 in our present peat-bogs, and of sti-eams flowing from them, is 

 coffee-brown in color, from the carbonaceous pai'ticles dissemi- 

 nated through it. These, subsiding in basins of quiet water, 

 form a carbonaceous mud which, when dried, is not unlike can- 

 nel coal. Where transpoi'ted by streams, and mingled with a 

 preponderance of earthy matter, the equivalent of bituminous 

 shales is produced. In the Carboniferous age, like causes pro- 

 duced like effects; and cannel coal is found holding such rela- 

 tions to cubical coal (ancient peat) and to bituminous shales, 

 that we can plainly read their closely connected histories. 



In attributing the carbonaceous matter of cannels to macerated 

 cellular plant-tissue, I would not be understood to exclude the 

 microscopic algae and protophytes (desmids and diatoms) from 



