10 REMARKS ON THE VEGETATION OF THE 
stone which fills up the pot, adheres to the upper part of the cavity, so 
that the trouble may go farther up into the stratum than is imagined. 
This trouble requires to be minutely investigated ; and the pavement upon 
which the coal rests should be examined under the trouble, to ascertain if 
it is in any way altered in its structure, as is the case with the coal. For 
my information respecting this interesting phenomenon, I am indebted to 
my much respected friend Mr Bap, who, I am happy to say, intends at 
an early period to direct his attention more particularly to these singular 
objects. 
Were further proof of the vegetable nature of coal wanting, the fact of 
the occurrence of Segenarie (Lepidodendra of STERNBERG) in the solid 
coal, the thin layers of incoherent carbonaceous matter, having much of the 
silky aspect of charcoal, alternating with layers of good bituminous coal, and 
bearing the form of calamites in a very perfect manner, should go far to 
establish the vegetable origin of these combustible beds. 
I shall now add some observations on the neighbourhood of Edinburgh. 
Here, again, I have been fortunate in obtaining many specimens of vascular 
cryptogamic plants, whose original substance has been transformed into one 
of the same nature as the sedimentary deposits in which they were en- 
tombed, with the exception of their bark or outer coating, which is always 
carbonized. The prevailing plants of this district, like those of the New- 
castle coal-field, appear to be Sigillarie, Lepidodendra, Stigmariz, and va- 
rious Calamites. 
I may here mention, that, in the neighbourhood of Burntisland, in Fife- 
shire, one of these vegetable fossils, referrible to the genus Stigmaria of 
BRoneniaRt, the Variolaria of STERNBERG, occurs in a limestone. This 
is a circumstance by no means of common occurrence. The limestone does 
not contain any coralline remains, so abundant in the limestones of the 
neighbourhood, and, in appearance, as well as in chemical composition, va- 
ries little from the limestone of the Portland oolite. A deposit of lime- 
stone also occurs at Hatton near East Calder, and at Burdiehouse near 
Edinburgh, containing impressions of terrestrial vegetables. This lime- 
