ave 



I 



■f 



s 



t 



■^\ 



\ 



anil' 



■te ii 



re II. 



fOOl 



:rati. 



jots 

 lie- 



> 



re' 



i. 



HUTTONIAN THEORY. 



153 



the coal having been worked only 



beds, 



place, and by an open pit, without any extenfive 



fubterraneous excavation, nothing is known with 



certainty. 



■ L 



In the Bovey coal too, I mull obferve, though 

 its beds have the ligneous ftrudure very diftind, 

 the clay interpofed between thefe beds, which 

 is but little indurated, contains a great deal of 

 coaly matter, in the form of thin flakes, inter- 



fperfed through 



So far as I kn 



no mineral veins nor fhifts, nor any bed of i 

 durated Hone, that accompany this coal ; fo th 

 though one cannot doubt of its vegetable orig 



fom 



doubt may be 



d 



the nature 



f the mineralizing 



ning 



perations 



which it has been fubjeded. The confideration 

 of thefe, however, does not belong to the prefent 



gument 



d the 



P 



f this femi 



mineralized coal, as it may be called, have 

 nothing to do with the general queftion, whe- 



ther 

 fubft 



wood 



ab 



d mineral-coal are the far 

 hich queftion, if the grad 



no r ca- 



tions are properly confidered, I thmk 

 fonable doubt can remain. 



141. One of Mr Kirwan's objedions to the 

 vegetable origin of coal, is founded on this fad, 

 that there is, in the mufeum at Florence, a cel- 

 lular fandftone, the cells of which are filled with 



luine mineral coal. ^' Could this, (adds he) 



have 



ge 



