a 
of the recently discovered analogy in the periods of rotation of - 
7 for withholding his assent to this law are :-— 
 # [have but recently received the species collected, and have therefore ha 
394 On the Law of Rotation of the Primary Planets. 
It seems strange that while so much speculation has been ex- 
cited in relation to the drainage of this swamp, so few lines of | 
levels have been seen, the only means after all, of settling this | 
important question. 
The soil on the margin of the ‘Everglades’ is composed of 
vegetable matter and white silicious sand which seems to be 
washed in by the rains from the ridges.* 
The best point for the examination of the limestone of the 
main land, is at Lewis’s Point, a short distance from the mouth of 
the river; the section is about twelve feet in height, and in a 
few hundred yards all the characteristics of the limestone are 
- finely presented 
It was curious to observe at this locality the influence of the : 
river on the mollusca. The only oysters that I observed occur ; 
here. I found also a Perna, which I do not find recorded among | 
the marine fauna of our coast, although the genus occurs fossil 
in Virginia and Maryland. 
a limestone so porous and soft as this, the existence of lime- 
sinks, subterranean streams and natural bridges is not surprising. 
What portion of the Peninsula is made up of this very recent” 
formation, I am unable to say, but as I have already stated, it 
must not be confounded with the tertiary of Tampa which 
doubtless extends to Charlotte harbor. 
The contour of the ridge surrounding the ‘ Everglades,’ taken 
together with the structure of the rock of which it is composed, 
and imbedded organic remains, leads very strongly to the con- 
clusion that it once occupied a position similar to that now occtr 
eys. And it is evident that an elevation of the 
Keys of about ten or twenty feet would produce a similar ridge, 
shutting out the sea from the space, at present, between the ree 
and the main land, and producing a second ‘ Everglade,’ differing 
from the present only in its greater comparative length. 
Tuskaloosa, Feb. 26th, 1851. : 
ie 
__ In the American Journal of Science and Arts, for March, 1851, 
I notice an article by Prof. Loomis, calling in question the tui 
the primary planets. The reasons assigned by Professor Loomis 
- I. That it gives an improbable period of rotation. to Uranus. : 
—— 
