Geological Society of London. 179 
honour as of the greater significance, since of all our scientific societies the Geological 
Society of London must be deemed tbat which in all respects is tbe most competent 
to form a judgment of those labours it has specifically named as justifying its decision 
in my own case. It is a somewhat trying ordeal, even to one of scientific acbievement 
far beyond anytbing to which I cau pretend, to bear his own work (as is usual on 
occasions such as tlie present) trumpeted forth fronv the Presidential chair before such 
an assemblage of eminent men, best capable of weighing their merits or demerits, as 
that I now see around me. I fear, Sir, that a good deal of the sunny colouring 
spread by you over whatever I may have been able to add to our knowledge of certain 
branches of Physical Geology, must become toned down to more sober tints, when, in 
future years, what I have been able to do shall be examined by the steady light of the 
study of the students and philosophers of a future age. It is given to no man so to 
interpret nature that bis enunciation of her secrets shall remain for ever unmodified 
by the labours of his successors. Nor am I vain enough to imagine that the two 
subjects for which you have principally awarded me this medal can be exempt from 
that which is the common lot of all advances in Science. 'What I have enunciated 
with respect to the laws of earthquake movements will fundamentally, I believe, 
adniit of little of very radical change by the future advances of Physical Geology ; for 
the laws I have assigned to seismic phenomena come so close to, and are such direct 
consequencesof well-understood physical laws, as to be, like those laws, immutable ; but 
in details future discovery eannot tail to alter something, and vastly to add to that I 
have been privileged to announce. For example, it was my own good fortune to 
ascertain, observationally and experiraentally, the depth below the earth’s surface 
whence the impulse came of the first earthquake ever submitted to measurement. 
That in the case of the great Neapolitan shock of 1857 proved to be only about eight 
or nine geographical milcs ; but it is highly probable that the depth of the centre of 
impulse of many great earthquakes may greatly exceed this, and may be found to bear 
some relation to the height of the greatest mountain-ranges adjacent. Thus my old 
friend, Gr. Oldham, after his examination of the region of the great Cachar earthquake 
a few years since in North-eastern India, found that its centre of impulse may have 
been thirty miles in depth from the surface. The views which I have enunciated as 
to the nature and origin of volcanic heat and energy, though I believe tbey will be 
ultimately found to be in the main a true interpretation of nature, must, I expect, 
be subjeet to large modification and addition in the future advances of knowledge. 
Our physical data in their numerical relations are still too defective to enable us to do 
much more at present than to sketch the general scheme of the laws of volcanic 
action, which must, by the way in which they fit into or explain many natural 
phenomena in widely diverse regions of nature, seem to afford credentials of their own 
reality in nature. 
In making these remarks, I have, perhaps, already exceeded the limit that properly 
belongs to an occasion like the present ; and, in conclusion, let me once moie repeat 
my thanks for the kindness, sympathy, and appreeiation with which you have to-day 
marked your approval of what little 1 may have been able to do for the advancement 
of our common object. 
The President then presented thebalance of the proceeds of the Wollaston Donation 
Fund to Mr. Robert Etheridge, jun., F.G.S., and addressed him as follows : — 
Mr. Robert Etheridge, — I have great pleasure in handing to you the balance of the 
proceeds of the Wollaston Donation Fund, which the Society has awarded to you as 
a testimony of their appreeiation of your industry and accuracy as a Palaeontoiogist. 
You have laboured with great success amongst the fossiliferous rocks of Australia, and 
now you are advancing palseontological science by describing the rarer fossils of the 
invertebrate series from the Scottish Carboniferous formation. In offering you this 
distinction, I venture to hope that its reception will stimulate you to further inquiiies 
into the Palaeozoic faunas. 
Mr. Etheridge replied Mr. President, — The recognition by the Council of the 
Geological Society of my labours, by the award of the Wollaston Fund, is both 
gratifying and complimentary to me. I have been and am still making gieat 
endeavours to elucidate some branches of our common science. For your award 
I beg to tender my sincere thanks. It will stimulate me to further exertions. 
The systematic study of the British Carboniferous Mollusca, to which I have more 
particularly confined my attention, has been for many years comparatively neglected, 
notwithstanding the vast amount of material gathered together through the energy 
and zeal of local scientific men, many of them distinguished members of our Society. 
