284 MR MILNE ON THE MID-LOTHIAN AND EAST-LOTHIAN COAL-FIELDS. 



of this coal. The following figure will shew the exact part of the seam occupied 

 by these interesting relics : 



1, Is a thin seam of fine cubical coal half an inch 1- 



thick. 2. 



2, Is a band of parrot coal from 2 to 4 inches thick. 



3, Is the division between the parrot coal and the ^• 



splint coal, and about one-fourth of an inch 

 thick; — along this line are the fishes' teeth 

 and scaleSj imbedded in coarse coal. 



4, Coarse splint, 1^ feet. 



5, Good splint, I4 feet. 



4. 



The fact now stated seems to be quite irreconcilable with the notion that 

 the vegetable matter that was ultimately converted into coal, could have ac- 

 cumulated on dry land, or any where else than in an aqueous medium of con- 

 siderable depth. 



I do not at present allude to the inquiry, whether this body of water was 

 salt or fresh, — or how the vegetable matter was transported. I wish here only 

 to shew, that the coal-strata must have been, in common with the other mem- 

 bers of the carboniferous series, formed by successive layers at the bottom of an 

 aqueous medium of some kind or other. I have said that this body of water must 

 have been of considerable depth : it is still more clear that it must have been of 

 considerable extent. For as several individual members of the series have been 

 traced throughout the whole of Mid-Lothian and East-Lothian, it is evident that 

 it must have covered these counties at least, and probably washed the base of 

 the present Lammermuir Hills, both on their north and on their south flanks. 



The next question, in our attempt to explore the origin of the several kinds 

 of strata constituting the coal-measures of this district, is, — From what sources 

 were derived the elements or ingredients which compose these strata ? 



That they were all derived from one and the same locality, or even from 

 the same quarter of the horizon, is extremely improbable. We can easily con- 

 ceive that the greywacke hills of the Lammermuirs should have supplied the 

 aluminous ingredients which compose the shales and clays of the district ; and 

 that the vegetation which covered them afforded, to a certain extent, materials 

 for the deposits of coal. But it is obvious, that these hills could not have pro- 

 duced the enormous quantities of siliceous matter which compose the sandstone 

 strata : for, in point of fact, silex enters, to a small extent, into the composition 

 of these greywacke rocks ; and, though it is probable that what is called the Old 

 Red Sandstone has been, in a great measure, derived from the Lammermuir 

 Hills, these red sandstones contain a much smaller proportion of silex in them 

 than the sandstones of the coal-measures. Indeed, it is obvious, that, had there 



