1810.] 
genuity and success, he shews, that the 
ruined ‘forests cf Europe have laid the 
foundation of the greatest part of the 
mosses in that quarter of the globe. On 
this foundation nature builds her work. 
An endless succession of aquatic plants 
rushing up with rapidity over the surface 
of these ruined forests, has furnished 
the materials of which all peat-moss is 
composed, 
So that the substance is entirely com- 
posed either of ligneous or aquatic 
plants, or of both. Of this there can be 
no doubt, after perusing these essays. 
{n order to establish this point, a learned 
and curious account is given of the an- 
cient forests of the north of Europe, in 
order to shew that they were abundant, 
and the reasons of this; and to point out 
the means by which they were destroyed, 
and by whom. From this account it is 
clearly: established, that ‘these ruined 
forests furnished materials for the for- 
mation of peat-moss. The leaves and 
sceds, and twigs and bark and roots of 
trees, being all blended together in a 
morass, became a soil fit for the growth of 
a variety of aquatic plants. By this 
means, this morass being filled up entirely 
with this accumulation of vegetable mat- 
ter, has been consolidated into peat- 
OSS. 
But as that substance differs in its 
chemical qualities from these recent 
vegetables, of which it is composed, the 
Bext objectof the Rev. ductor is to shew : 
il. The changes which these materials 
must have undergone in the lapse of 
ages. With this view he gives an inter- 
esting chemical. discussion on the dif- 
ferent changes which both animal and 
vevetable matter undergo in different 
medicines. 
ject it appears, that the-same materials 
which furnish vegetable mould when 
exposed to the atmesphere, are con- 
verted into moss when immersed in 
water, especially if that water he stag- 
nant, and possessed of an antiseptic 
quality, and placed in a low and nearly 
equable temperature. On account of 
these peculiar circumstances, these ve- 
getables do not undergo the putrid fer- 
mentation: of course, they contain the 
orginal elementary principles of which 
they were composed. 
The carbon and hydrogen, the phos- 
phorus and tannin, the gallic and other 
vegetable acids, the metallic, and other 
particles of this vegetable matter, being 
all deposited in these circumstances, 
furnish the materials of all peat-moss. 
From this view of the sub-' 
Observations on Dr. Rennie’s Essays on Peat Afoss. 
og 
As a proof of this, these materials or 
elementary principles, may still be de- . 
tected in that substance. If so, peat- 
moss is nearly homogeneous to coal, and 
other bituminous matter. The author's 
object is therefore to shew: III. That 
there is an obvious alliance between 
peat-moss and all the varieties of bi- 
tumen, whether liquid, solid, or aéri- 
form. With this view, a vast variety 
of facts are stated to shew that similar, 
traces of vegetable matter, such as the 
trunks, branches, fruits, and leaves, - 
of trees, and sometimes of. aquatic 
plants, are detected in coal and jet, 
as in peat-moss. When all these 
facts are carefully collated together, 
little doubt can remain as to the vege- 
table origin of all. these substances ; 
more especially when it is added, that 
peat-moss, which is obviously and alto- 
gether composed of vegetable matter, 
may, by compression in combination 
with certain chemical agents, be con- 
verted into a substance that cannot be 
distinguished either by its colour, cun- 
sistency, or qualities, from coal. 
There are besides many reasons to 
conclude that coal, at one period of its 
formation, has been in a soft and pulpy 
state, like peat-moss. Ifso, compression 
alone would consolidate it; and all coal, 
wheréver it has been discovered, has 
certainly been subjected to compression, 
Above ail, as these substances all 
yield, on chemical analysis, nearly the 
same elementary principles, and in the 
same order, and sometimes in the same 
proportion, and as they are sometimes 
found in alternate layers, one above or 
below the other, there can be little 
doubt that they are nearly homogeneous, 
and all of vegetable origin. 
But naptha, petroleum, mineral pitch, 
and all the varieties of liquid bitumens, 
may be extracted from each of these 
substances, by distillation. If theres 
fore the latter be of vegetable origin, 
there can be little doubt that the former 
may all be traced to the same source. 
And there is the strongest probability, 
that as all the solid kitumens are formed 
of the elementary principles of vegetable 
matter, so all the liquid bitumens are 
evolved from them by a process similar 
to distillation on a large scale, in the 
vast laboratory of nature. 
But if all these substances bear so 
near an alliance to each other, it may be 
expected that they will all be possessed of 
similar qualities. The Rev. doctor theres 
fore proceeds: 1Y.To point out che quali- 
tice 
