685 
now specially advert is, that in his skilful analysis of this memoir 
our eminent foreign associate admits floating ice as a vera causa to 
explain the drift of blocks, just in the same manner as in common 
with Lyell, Darwin, and others, I have been endeavouring to explain 
the phenomenon during the last three years, and thus the inference 
which was drawn from plain facts is admitted, viz. that the chief 
tracts covered by erratic blocks were under the sea at the period of 
their dispersion. (Sil. Syst. p. 536.) 
Thus far had I written, Gentlemen,—in short I had, as I thought, - 
exhausted the glacial subject at all events for this year,—when two 
most important documents were put into my hands. The first of 
these is the discourse of my predecessor, who has so modified his 
first views, that I cannot but heartily congratulate the Society on 
the results at which he has now arrived. I rejoice in the prudence 
of my friend, who has not permitted the arguments of the able ad- 
vocate to appear as the sober judgment of so distinguished a Presi- 
dent of the Geological Society. In fact, it is now plain that Dr. 
Buckland abandons, to a great extent, the theory of Agassiz, and 
admits fully the effects of water as well as of ice, to account for 
many of the long-disputed phenomena. Whilst this admission in- — 
volves the concession for which we have been contending, viz. that. 
the great surfaces of our continents were zmmersed, and not above 
the waters when by far the greater number of the phenomena on 
the surface of rocks was produced, I reject for those who entertain 
the same opinions as myself, the simple division into “ glacialists” 
and “ diluvialists,” into which Dr. Buckland has divided the com- 
batants on this question; for to whatever extent the former title 
has been won by Agassiz and himself, we who have contended for 
the submarine action of ice in former times, analogous to that which 
we believe is going on at present, can never be merged with those 
who, under the name of diluvialists, have contended for the rush of 
mighty waves and waters over continents. Besides glacialists and 
diluvialists, my friend must therefore permit me to call for a third 
class, the designation of which I leave to him, in which some of us 
desire to be enrolled who have advocated that modified view to 
which the general opinion is now tending. 
The other point to which I allude, and bearing at once on this 
view, is a discovery which our Librarian has just made without — 
quitting the apartments which he so truly adorns. In the Ameri- 
can Journal of Science for the year 1826, Mr. Lonsdale has de- 
northern drift to the flanks of the Ural Mountains he is decidedly in error, 
for there is no coarse detritus whatever on the fianks of that chain, whether 
derived from the north or from itself. Of the Tehornoi-Zem, or black earth 
of the central regions of Russia, to which, quoting Baron A. de Meyendorf, 
M. de Beaumont refers in a long note, I will now only say, that having stu- 
died the nature and extent of this singular deposit over very wide regions, 
I intend, with the help of my fellow-travellers M. de Verneuil and Count 
Keyserling, to lay before the public very shortly a sketch of its relations to 
the northern drift and other superficial deposits of Europe. 
