224 
Nor do I know of any contradiction to their observation, except 
in a solitary and very anomalous circumstance related by Lord 
Cromartie, in the Philosophical Transactions^. By his Lordship’s 
account we learn, that in a moss near the town of Eglin in Murray, 
though there is no water which communicates with the moss, yet 
for three or four feet of depth in the moss there are little shell-fish, 
resembling oysters, with living fish in them, in great quantities, 
though no such fish are found in the adjacent rivers, nor even in 
the water-pits in the moss, but only in the solid substance of the 
moss. Dr. Darwin considers this as a curious fact, which not only 
accounts for the shells which are sometimes found on the surface of 
coals, and in the clay above them, but also for the thin stratum of 
shells which sometimes exists over iron ore. 
The presence of light vegetable matters, and of small insects, 
such as flies, certainly at the first thought, appears to yield in- 
disputable evidence of the truth of that opinion which supposes 
amber to have originally been the gum or resin of a tree ; and 
which, whilst adhering to the tree, had thus caught these substances, 
which a conttnued effusion of the same matter had thus involved. 
But supposing this to have been the case, and that this substance 
had become buried in the earth, still its bituminous nature remains 
to be accounted for. It once indeed appeared to me as far from 
impossible, that the vegetable gums or resins inclosed in the mass 
of vegetable matters passing into the state of bitumen, might with 
them be pervaded by the fermentative influence ; and, as actually 
happens with other vegetable matters, lose little, if any, of their 
original form and appearance. But maturer consideration has 
shown that the opinion of the learned annotator on the works of 
Pliny is that which best accords with all those phenomena, which 
appear so contradictory, if regarded in any other point of view. 
* Philosophical Transactions, No. 330. 
