154 Book Notices. 
He questions whether the time of rotation of the still atmosphere i is 
the same as that of the earth; and suggests that this circumstance 
may perhaps explain the slow rotation of the magnetic poles of the 
earth. 
Physicists will be slow to accept Mr. Quetelet’s novel ideas, on the 
constitution of the atm dame ee as they are by experiment 
a ed 
ished tad and as the coefficients of expansion for oxygen, nitrogen 
and carbonic — are practically identical, it seems to follow as a neces- ~ 
sary consequence of this law that the constituents of the atmosphere 
above the regions sininds <nown by aéronauts have the same uniformity of 
chemical constitution, as is shown by experiment in all heights hitherto 
this u 
lower parts of the air—as is implied by Mr. Quetelet’s statements. His 
argument requires ‘hase distinct layers or strata of atmosphere—the lower 
or unstable atmosphere—above this a stratum of pure oxygen of great 
. : 
l 
contribution to meteorological science, and the poping ae views. here 
wigs ected to are wholly aside _ from its _great merit as 
We find under the notice of seroars and Brown counties some mention 
of the new gold region of Indiana, at Hamlin’s fork of Salt Creek. Dr. 
Owen expresses the opinion that the gold is invariably associated with 
drifted quaternary material derived from a = at least from four to 
six hundred miles distant in a northerly direct 
As these facts, if fully substantiated, open up ieltiins of great geologi- 
~ eal importance, it is to be hoped that ‘the region m gi rath er investi- 
gated and the origin of the gold be os tt beyond do 
The mean elevation of the lan i is a little over 678 fect 
the easurement of 208 stations. Lake Vichigas is 610 feet above sea 
level on anthionty- of the late Mr. Ellet; Messrs. Blodget and Lapham 
make it 591 and 600 feet. A depression of 80 or 100 feet, therelonesk 
_the level of the state, would open Lake Michigan to the Galt 
by the valley of the Mississippi, and in one place in Lake tee 
over 20 miles long and in no place 100 feet deep, cme ‘elect this 
eeiaion through the Llinois river. 
