390 



COAL AND LIGNITE 



The presence of marine remains, which is supposed to be an essential 

 distinction between the Lignite and Coal series, would leave but little doubt 

 of the classification of the mineral in question : unfortunately, a very strict 

 search has not discovered organic remains of any description : in conformity 

 therefore to the experience of others, and particularly of Mr. McCulloch, 

 who remarks, that marine remains occur in all the Lignites, I decline giving an 

 opinion on a subject intricate in itself, and upon which so much uncertainty 

 prevails even amongst the first Geologists. 



The certainty of this mineral being coal, is rendered also less clear, 

 from a further discovery of a carboniferous deposit in the same range of 

 hills ; in the proximity of similar rock formations ; and in the presenccj 

 of a variety of the blue clay or shale, described in my last notice, which 

 bears so decidedly the character of a Ligneous deposit, from the abso- 

 lute exposure of trunks or roots of trees in a state in ore or less Bituminized, 

 as to leave little doubt in my mind, that the venous appearance of the 

 seams at Silanit which 1 did not satisfactorily account for at the time, 

 was nothing further than the appearance natural to the ramification of minute 

 branches or roots of trees ;* more particularly, as the extreme high angle 

 at which they were placed, together with the irregularity that prevailed 

 in their position, would make it difficult to reconcile the arrangement with the 

 outcrop of regular seams of coal ; allowing, therefore, the possibility of an 

 excavation discovering a coal series at this point, we may with safety refer 

 the mineral found, either to Lignite itself, as defined by McCulloch, and 

 with which it agrees in every respect, with the exception of the proximity 

 of marine remains ; or to some of the intermediate grades existing before 

 the approach to coaL 



* Coal pipes, English Mines. 



