195 
letter XX. 
EXAMINATION OF OPINIONS RESPECTING THE ORIGIN OP PEAT 
aboriginal FORMATION... .a MARINE DEPOSIT MINERAL ORIGIN 
floating islands A RECENT VEGETABLE SUBSTANCE. 
Although I encourage the hope, that the circumstances adduced 
are such as will be likely to be successful, in establishing the opi- 
nions I have offered, respecting the origin and nature of this sub- 
stance ; yet something more remains to be done. The opinions 
already advanced, on this subject, have a claim upon our attention; 
and although the greater part of them may not require a formal 
refutation, others will require to be examined, that it may be de- 
termined whether they offer a satisfactory explanation of the pro- 
perties which are possessed by this substance. It is likewise incum- 
bent to determine whether those particular circumstances, which have 
been supposed most powerfully to support the h^qiotheses which have 
been already advanced, militate against, or favour, that which is here 
attempted to be established. 
The first opinion I shall notice, is that which supposes peat to 
have existed, in its present form and state, from the creation of the 
world. In opposition to this opinion, it must be sufficient to ob- 
serve, that peat is composed of substances which bear the indu- 
bitable marks of having existed in another state ; also that there 
is an abundance of instances of its formation going on, even at the 
present day. . 
The hypothesis, which supposes it to have been formed by 3- ^ 
minous deposit from the waters of the sea, must be rejecte , ^ 
its being impossible thus to account for the prodigious quantity o 
