A, Hinrichs on the Density, Rotation, and Age of the Planets, 49 
Kant and sonlow: according to which the more distant members 
were first developed. Hence it seems to be worth the while at- 
tentively to fot out the consequences of this hypothesis in: an 
analytical form, as only thereby it will appear, whether the planet 
Uranus disagrees with the theory itself, or simply with the de- 
ductions of its advocates. 
The Density 4 of the planets must depend, according to this 
theory of evolution and condensation, both upon the distance r 
in the original globe and upon the condensation in time, i. e. 
age #; as the “density was decreasing from the center of the 
nebulous globe, and is increasing in time, we have obviously 
dA dA 
dA= Gio <r (14) 
marr’ the differential dine represent positive, numerical 
values 
Thus it appears that the conclusion of a regularly decreasing 
density demands d?=0; indeed, so far as we are aware, no 
has as yet pointed out the influence of age on the density of 
the planets. 
‘It is evident that, if the differential coéfficients of A in regard 
da=‘3dd—“dr (15) 
which with the simplest possible a gives the integral, 
a Od ? (16) 
where now a, the oan: distance, enters instead of r the radius 
vector, and A=1, a=1, #=1 for our earth. In order to see 
how far this fount represents the actual pepe let us 
culate o from the known Moser! of A anda; (16) g 
A 
a Mean. 
Mercury, 38 ae “66 
Venus, 79 i. q "83 
Earth ~ 100 1:00 1:00 
152 96 1°39 : 
J Upiter, 5°20 24 “91 a 
9°54 “14 15 1-28 
Uranus, 19°18 18 2°89 2 
Neptune, 30-04 : 13 513 
5 
Am. Jour. _—— Srrizs, VOL. XXXVII, No, 109.—Jax., ae 
