56 
BEPOBT— 1847* 
19. Hypothesisof thefonner 7iehti.losif}/ofthe Solar Si/siem . — Tothosewto 
are disposed to admit the adequacy of the evidence in favour of the former 
fluidity of the cartli, anotlier question will naturally present itself, — Was the 
state of fluidity its primitive state, or did the matter composing it pass from 
an anterior gaseous state to the state of fluidity above contemplated ? If that 
matter was once combined w Ith a quantity of heat sufficient to hold it in a 
state of fusion, why should it not at a previous time have been maintaluod 
by still greater heat in the state of an clastic vapour ? The one hypothesis, 
considered merely as such, is as admissible as the other: but here we should 
be careful to observe the difference between the force of the evidence abore 
adduced in support of the one hypothesis, ami the want of all equally distinct 
evidence in confirmation of the other. I do not speak, of this want of evi¬ 
dence of the former gaseous form of the matter of the earth, or rather of that 
composing the whole solar system, os necessarily arising from the nature of 
the case, as it, for instance, the transition from this hypothetical to the pre* 
sent state of the system wore apparently opposed to well-established physical 
principles; but 1 would assert, that no one has yet been able to explain 
distinctly, and otherwise than hypothtrtically, how, in accordance with phy¬ 
sical priueiples, and by the operation of known causes, that transition could 
be effected. WhaU'vcr disposition, therefore, wo may fed in favour of the 
hypothesis that the whole solar system was once a nebulous mass, that opi¬ 
nion should be liidd with the rt'serve which ought to be inspired by the im¬ 
perfect evidence on which it is at present founded. 
1 lie hypothesis in question has ilerivcd some support from the analogy 
which has been conceived to exist between the state of the solarsystcmwhich 
It supposes, and those nebulous masses observed in such numbers in the dif¬ 
ferent regions of space. So far, however, as this support has been derived 
by extending the analogy to existing nebulosities generally, it has doiibtlesJ 
ecu weakened ly the fact, that the more our telescopic power of vision has 
been perfected, the greater fia.** been the niinibcr of nebuhe which have been 
''“I**® distinct stars ; and also by the inerhable infe- 
be adln ?.. I M 'P till our tdescopic power shall 
^ object, however, to cater further into 
!liP hvS""'* ^ proceeded thus far only to show that 
on evideml ^olixr system ists at present 
aruumcm in f ^^“5 a«d imperfect to admit of our deducing from it any 
iscZmrehJS^^ validity of which 
the calculati-H nn I ^ drawn from the exact accordance of 
Z nS L "h ‘^Jliptioides. If the analogy with all exist- 
former fluiditv w mtii ^.y ^'^o^ving them, the evidence in favonr of 
resfe,—evidJncedZvp i^^ ***at on winch the supposition of its fonner fluidity 
consequence of the 
and.aUeast.probablLoiditions/^^““^ under defcrimnate, 
biode in which existing vnl ^y ^ operation of simple causes the 
fluid U, JXri“Z.ZdT? huve origiuated in the 
be recollecrurLlw fu™erly conetituted thegSbe. Itmu-d 
ing to be admitted the vali,?b«. ‘ ? accuracy of the general reason- 
uaiwttcd, ti,c val.d.ty ot our coodusioui. sUll depends on the truth of 
