88 
Run Mountain stood, as I found by compass, N. N. E. by E. from the Sweet 
Springs; and Peter’s Mountain, of which I could get a peep through the trees, 
bore east of the place where I stood. 
“ Here was an extraordinary phenomenon ! an immense deposit of travertin, 
lying three hundred and fifty feet above the level of the spring from which it 
probably was derived. It seems to be susceptible of no other explanation than that 
the level of the valley w T as, at some remote period, much higher than it is now, 
and that the springs were, at least, at this level. The Snake Run Mountain is a 
large limestone outlier from Peter’s Mountain, such as are constantly found in the 
valleys. Before these were scooped out by the retiring currents, it is probable 
that the whole surface of this now deeply-sulcated region was continuous, and that 
the springs issued from the bottom of the ocean. When the valleys were swept 
out, these knobs, hills, and spurs, being hard, compact, transition limestone, re¬ 
sisted, and were left; whilst the conglomerates, shales, and sandstones, were car¬ 
ried away: since that period the softer parts of the formations, occupying that 
part of the valley where the springs now are, have been gradually worn down, and 
a new direction given to the stream ; whilst the old travertin remains a monument 
of the ancient level, and one of the strong geological proofs of the process of 
denudation.” 
A considerable portion of the communications now under consideration relate 
to subjects more or less connected with the mineral resources of some parts of the 
United States, and which, though of the highest importance, naturally possess a 
more local interest than other parts of the volume. The contributions relating 
to organic remains contain some new and valuable information ; but the limits of 
our present article will not admit of extending our analysis to them, and we must 
therefore refer our readers for points connected with their history to the work 
itself. 
There is certainly one subject upon which we cannot help expressing our 
regret, and that is, that the present volume should be so destitute of information 
upon the tertiary geology of America. With the exception of a short notice, by 
Mr. Conrad, upon a portion of the Atlantic tertiary region, we find no allusion 
whatever to the supra-cretaceous deposits, which are so largely developed in some 
parts of the United States. The important results which have attended the exa¬ 
mination of the beds above the chalk in England and the adjoining continent; the 
wide field which has been opened for theoretical inquiry into the causes of pheno¬ 
mena which are there presented to us ; and the connection existing between the 
newest rocks of this period and those deposits which are accumulating from the 
operation of agents now in activity, give a degree of interest to facts bearing upon 
the history of that epoch which does not attach itself to any other department of 
geological investigation. 
We are not, it is true, entirely without sources of information upon the ter- 
