' Miscellanies. 197 
In a wide sense then, says the memoir, it may be stated that the cen- 
- tral portion of the continent is surrounded on the north, east and west, by 
a chain of primary formations, and that the entire space included betwixt 
the Alleghany and Rocky mountains, constitutes the great valley of the 
Mississippi. In so terming the immense country intermediate between 
these two ranges of mountains, the reader is guarded against the idea, 
that this tract is filled up with alluvial or tertiary deposits, or of supposing 
that it maintains an uniformly low level. This, as stated, can only be said 
of that portion situated between the Ozark and other hills, and the western 
side of the Alleghanies, about one hundred miles east and west of the 
Mississippi. 
The Ozark hills, Dr. Daubeny, who had an opportunity of examining 
them in person, describes as consisting of clay slate, quartz rock, and 
sandstone, except near the mining district of Missouri, where porphyries 
and specular iron, in immense masses, have been protruded. 
The several ores of the unstratified rocks are noticed, as are also the 
other minerals with which they abound. ‘The dykes so common in New 
England, are mentioned as establishing a distinction between the rocks on 
the east, and those on the west of the primary chain, and as furnishing 
evidence of frequent igneous action subsequently to the elevation of the 
Alleghany mountains. ; ‘ 
The memoir next proceeds to describe some of the later formations: i. e. 
the fossiliferous rocks of New York, and those of the same relative posi- 
tion in the more southern states, with their mineral and paleontological 
contents. This, although mostly drawn from the able reports of the gen- 
tlemen engaged in the surveys of these formations, is yet interspersed with 
much interesting matter, drawn from the observation of the writer. Of 
this character are the remarks upon the Falls of Niagara, which are well 
worth the careful perusal of all who feel at all desirous of information in 
relation to their origin. The difference of level between the country be- 
low and that above Queenstown, has, it is well known, been generally 
ascribed to a subsidence of the former. Dr. Daubeny, however, from no- 
ticing that the strata from this place to Lake Erie appeared to dip some- 
what south, (a fact, which, as stated in a note annexed, has been since 
verified by Mr. Hall,) is inclined to the opinion that this portion has been 
elevated. In relation to the falls, in other than a geological view, Dr. 
Daubeny, expresses himself as having been at first somewhat disappoint- 
ed, though subsequently this feeling gave way to others of a different 
character. His own account is as follows: 3 
“With respect to the fall itself, considered in a picturesque point of view, 
or as influencing the imagination and feelings, it may seem an odd con- 
fession to make, that my first feelings, on visiting it, were not unmixed 
With disappointment. Of an object so long known by report, each person 
before he reaches the spot conjures up in his mind some sort of idea, 
