compared with the New World. 255 
By the aid of these facts, it has become possible to de- 
termine the extent of seas in the different geological epochs, 
and also to indicate, on charts of a new description, the points 
of their greatest depth, and even the contours of their coasts. 
These beaches, like the continents of which they formed a 
part, rose above the seas, in proportion as the latter sub- 
sided into the limits which they could not surpass. 
The knowledge of these facts, for which we are indebted 
to the spirit of observation by which science is now directed, 
is one of those things of which in modern times we have 
most reason to be proud. It is perhaps as important, though 
less useful, than that which enables us to assign, with a re- 
markable degree of precision, the depth at which we may expect 
to meet with sheets of water sending forth spouting springs. 
Who of you, gentlemen, can forget that one of the most 
beautiful applications of a principle so simple and fruitful in 
results has been made in sinking the famous wells of Gre- 
nelle ? 
Similar inductions are, in fact, scarcely possible, except 
in countries well known in their geological relations. It 
remains, therefore, to discover a means of supplying this 
method of appreciation; it is a subject well worthy the 
attention and research of those who are interested in the 
progress of the useful and practical sciences (See Note 15). 
_ Another peculiarity of the ancient world not less remark- 
able, and which relates to the epoch when seas were of much 
greater extent, is, that during this long interval fresh waters 
do not appear to have existed on the surface of the globe. 
At least the aquatic vegetables and animals of that period 
present no characters which can lead us to suppose that they 
inhabited waters not saline. It is not till after the separation 
of interior seas from the ocean, that we can, without hesita- 
tion, distinguish fresh water beings from marine species 
(See Note 16). 
The vegetation of the early ages, luxuriant as it was, does 
not afford that almost infinite variety which characterises the 
present flora. If Man had existed at that time, it would have 
been vain for him to seek, by change of climate, or even of 
hemisphere, for those profound impressions which the rame- 
