Miscellanies. 395 



13. Bituminization of peat and conversion into coal. — At page 73 

 of the present volume this fact is mentioned ; the following more full 

 notice of it is contained in Dr. Charles T. Jackson's Report on the 

 Geology of Maine, pp. 80, 81. 



" In Limerick we examined the peat bogs on the estate of Mr. Eben- 

 ezer Adams, where a very remarkable substance is found rcsemblinar 

 exactly the cannel coal. It is found at the depth of three feet from 

 the surface of the peat bog, amid the remains of rotten logs and beaver 

 sticks, showing that it belongs to the recent epoch. The peat is 

 twenty feet deep, and rests upon while siliceous sand. This recent 

 coal was found while digging a ditch to drain a portion of the bog, for 

 the sake of obtaining peat as a manure ; about a peck of it was saved, 

 and served to supply us with specimens. On examination, I found 

 that it was formed from the bark of some tree allied to the American 

 fir, the structure of which may be readily discovered by polishing sec- 

 tions of the coal, so that they may be examined by the microscope. 

 " It contains in 100 grains. 



Bitumen, - - - - 73 



Carbon, - - - - 21 



Ox. Iron, - - - - 4 



Silica, ..... I 



Ox. Manganese, ... 2 



100 



" This substance is a true bituminous coal, containing more bitumen 

 than is found in any other coal known. I suppose it to have been 

 formed by the chemical changes supervening upon fir balsam, during 

 its long immersion in the humid peat. 



" The discovery of the recent formation of bituminous coal, cuts the 

 gordian knot which geologists and chemists are endeavoring to un- 

 ravel, and shows that the process is still going on. The diiFerence 

 between bitumen and resin is not very great, and the absorption of a 

 small quantity of oxygen is all that is required to effect the change. 

 Other localities of this curious substance, may be found by searching 

 the numerous peat bogs in other parts of the state." 



The coal measures of Mansfield, Mass., are in the conglomerate 

 or graywacke; a fact that would not be readily admitted in England. 

 It is evident that our conglomerate rests on sienite, and alternates 

 with the argillaceous slate rocks: also, that its mineralogical compo- 

 sition and structure, as well as its position, stamp it as a graywacke 

 formation ; and yet it is full of coal plants ! I have collected fourteen 

 or fifteen species there during three visits to the mines.* 



Extract of a letter to the Editor from Dr. Jackson. 



