68 SKETCH OF THE LIFE AND CHARACTER 
In the first part of this paper, he exhibited the 
proof of the vegetable origin of coal, showing how 
peat is formed from the decomposition of vegeta- 
ble matter, and how it might, after a sufficient 
lapse of time, under the ancient conditions of the 
globe, be converted by pressure and exclusion 
from the atmosphere into coal. In the second 
part, which proposed to explain through what 
processes in the immense laboratory of nature 
this conversion is effected, he assumed in place 
of the old notion, that the level of the sea had 
varied, the now generally received theory of 
the successive elevation and subsidence of the 
land, proved by effects still in operation ; and 
instead of supposing the vegetable matter ulti- 
mately converted into coal, to have been drifted 
into its present situation, he expressed, as the re- 
sult of his inquiries, his belief, that the trees and 
other vegetable matter from which the beds of coal 
are derived, grew on the identical spots which the 
latter now occupy. The process—which he illus- 
trated by very intelligible drawings—he conceived 
in general to be this :—that over an extensive dis- 
trict there were partial subsidences of surface, 
clothed with a luxuriant vegetation, which was 
then covered up and pressed down by an accumu- 
