Ixxviti PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 
Totness; in fact, into districts the organic remains of which have 
engaged so much attention under the name of Devonian fossils. 
There has also been a paper by Mr. Richard Couch, entitled 
‘Remarks on the Present State of Geology in Cornwall,’ in which, 
while taking a general view of the actual knowledge respecting the 
geological structure of that county, he remarks, speaking of the gene- 
ral range of rocks, that after passmg the Looe river westward, the 
Devonian fossils become more rare, that the organic remains assume 
more of a Silurian character, and that the peninsula formed by the 
Looe and Fowey rivers is composed of rocks partaking of the cha- 
racters of the Devonian and Silurian series. Further westward, Mr. 
Couch observes, the characters of the fossils change: “there are 
many things to remind us of the old red sandstone, and yet suffi- 
cient to recall the idea of their being the deposits of the Upper 
Silurian rocks.’ It can be only by a careful study of all the great 
bends of the sedimentary rocks of Cornwall, with a constant atten- 
tion to the minor flexures, and by an endeavour to trace out either 
overlaps or the fining off of beds, amid the contortions, that the true 
history of these deposits will appear. 
Sir Charles Lemon, in a notice on the stump of an old tree, found 
in Heligan, pomted out many peculiar circumstances attending its ~ 
mode of occurrence. He infers that the phenomena may be ac- 
counted for by an extensive change in the face of the country, due | 
to local causes, since the time of the great drift, and after the growth 
of existing species of trees. There was also a notice by Mr. Edmonds 
on the rapid diminution of the sand-banks of Mount’s Bay. Details 
are given of the loss of land sustained, and the removal of sand has 
been so considerable, that not only a meadow has been carried away, 
which seventy years since lay outside the sea-wall at the entrance to 
Newlyn, as well as ground occupied formerly by cottages and gar- 
dens near Penzance, but numerous rocks between high- and low- 
water mark, forty years since buried beneath four or five feet of 
sand, are now uncovered. The author attributes this loss to the 
quantity of sand removed as ballast for the shipping at Penzance, 
and employed as manure. 
During the past year also, Mr. Percival Norton Johnson read a 
paper to the Society upon the electric action affecting metalliferous 
deposits. He has availed himself of every opportunity in endeavour- 
ing to establish, by observation and experiment, the effects of various 
rocks acting as positive and negative poles for the deposit of metal- 
liferous substances. He infers that the existence of such deposits de- 
pends not only on the difference of the rocks, but also that the electric 
action must be kept up by the moisture percolating through the 
joints or cleavage of the rock in which they are found. From his 
experience he concludes that a bunch of ore or metalliferous deposit 
is never seen without proving its origin to have been the percolation 
of water through the joints or cleavage of the adjacent rock, with a 
difference of character in the contiguous rocks. The researches of 
Mr. Were Fox and others on the electric condition of mineral veins, 
and on the manner in which the ores of the metals have been ac- 
