G. Hinrichs on Planetology. 47 
The reason of this neglect seems to be the incomplete state in 
which even Laplace himself left the theory. Direct observation, 
moreover, seemed: to contradict some laws given as necessary 
consequences of this hypothesis. 
We have already, in a former article,’ tried to vindicate the 
theory in this last respect by showing that the hypothesis is 
really confirmed even in these apparently contradicting observa- 
tions. We will now endeavor to give a somewhat more com- 
lete development to the fundamental principles of Kant and 
aplace, and to exhibit the exact position of the nebular theory 
itself, hoping thereby to show that this theory, if we only study 
it earnestly and patiently both by experiment and analysis, fully 
eserves our confidence. 
As this subject is as vast as it is difficult, we beg the critic 
always to keep in mind that we do not pretend to give a treat- 
ise, but merely offer an ¢niroduction to shia almost new field o 
analysis, 
commence with a short survey of the fundamental prin- 
ciples and the aim of the theory of the solar system, in order 
clearly to understand why the nebular theory is necessary, what 
c will have to accomplish, and how far it already has done its 
uty. 
$1. The fundamental constants of the Solar system. 
a 
e. 
The constants of the solar system now exclusively deduced from 
observation are: 
- The mass, m, of the planet. 
* The density, rotation, and relative age of the planets: this Journal, Jan., 1864. 
* Fracastor ae Bailly, Histoire de en moderne; vol.i. Paris, 1779. 
tclaircissements, livre iv, § 23, and livre viii, §27. eet 
F "a | importe extrémement den bannir out empirisme fan “ed — a n’em- 
