Dr Fleming's Remarks on the Modern Strata- 121 
ther explanation of these phenomena has been offered by Mr 
Henslow, Professor of Mineralogy in the University of Cam- 
bridge *. He considers the deluge of Noah as having taken 
place by water at that time added to the Earth and that, 
since that period, “ this extraneous supply of water'''’ has been 
absorbed, to a certain extent, by the solid portion of the Earth ; 
but a portion still remains, covering with the sea those forests 
which were, in its antediluvian state, above its level. If these 
forests grew on rock, the explanation here offered might seem 
plausible ; but they are supported by a stratum of lacustrine 
silt, and in this respect exhibit a common character. Of the 
nature of this supporting stratum, the learned Professor had not 
been aware, else it would have led him to assign to the forests 
a different origin. 
The Carsesy especially those of high level, of the Forth and 
the Tay, seem to consist of lacustrine silt, and to have been pro- 
duced in a fresh-water lake, to which the sea, in its ordinary 
movements, did not extend. The proofs, in support of this opi- 
nion, will shortly be laid before the public. 
In some cases, the different beds of lacustrine silt seem to 
have been repeated, and two or more series, each consisting of 
sand (or clay) marl, and peat, occur in the bed of the former 
lake. In such cases, the first or lowest layer of peat, may have 
been covered by detritus of sand during a flood, placing the lake 
in some measure in its original condition ; or the peat itself may 
be regarded as detritus, brought from a higher level in the form 
of mud. 
Marine Silt derives its origin from the detritus of rivers, and 
the washing operations taking place on the sea-shore. At the 
mouths of rivers, the matter deposited has many of the charac- 
ters of detritus, united with those of marine silt. Farther off 
the shore, the marine silt is deposited under the influence of cur- 
rents, forming shoals or banks, as the Dogger-bank, the Long- 
fortus and Jutland-reef in the German ocean. The marine-silt 
receives the remains of sea-animals, which, in some instances,, 
contribute greatly to its increase, as the coral reefs abundantly 
testify. It must likewise, in the case of great floods, receive the 
relics of terrestrial animals. Mr Stevenson has published the 
• Annals of Philosophy, Nov, 1823, p Sil-. 
