211 
ISI 1.3 of ihe proxiniaic Cause of Gravitaiion* 
I conceive also, that that pressure of 
the sul)stratum, fluid, or medium, of the 
universe, on ail extraneous bodies placed 
within it, sucii as solidity or matter., must 
jnechanicaliy produce the phenomenon of 
.gravitation; or, in other words, I conceive 
that graritatioriy or the phenomenon 
,of inareiial bodies rnshin'j; together, u 
occasioned by the solicitations of the nr,l~ 
formUi-dijfused substratum of' the nni- 
verse, to pervade and enter all bodies, 
thereby oecofioning an external pressure 
upon thepi in the ratio of' their resistance 
or solidity. 
The objection to a nniversaUy per¬ 
vading medium, founrled on its supposed 
resistance to the motion of the planets, is 
to tlie last degree unphilosopiiical, Caiise 
and effect in nature, are necessarily al¬ 
ways equal; a?id, in the original arrange¬ 
ment of their powers, it would havebecn 
as easy to make planets move through 
water, as through any medium ten thou¬ 
sand times rarer than water. Is it not 
also mure accordant'with the analogy of 
nature, and with the evidestt similitude 
of the solar and planetary bodies, to 
suppose them existing and moving in 
one common medium, possessing pro¬ 
perties essential to animal and vegetable 
life, and to the propagation of heat and 
light; than to suppose that each body is 
surrounded by insulated, and peculiar, or 
.^itnilar, fluids, generated near its on n 
surface; and that the prodigious spaces 
between them have nothing in common, 
or are an absolute vacuum. 
Nor is it asking more of fairb and 
judgment to give credence to the ex¬ 
istence of a universally pervading me¬ 
dium which necessarily presses every 
extraneous substance from every side, 
than to ask of faith to believe, as the 
Newtonians do, tl>at attractive efiln- 
via pass between bodies that are said 
to he mutually attracted ; or which, in 
piore correct language, rnutualiy fall to¬ 
wards each otiier?—How are effluvia to 
effect the pheHomena of attraction ? 
— How are they to take hold of an' ob¬ 
ject?—What connection continues be¬ 
tween them and the body, whence tliey 
flowed, to occasion them to solicit another 
{)ody to return with them back to it?—- 
,|n short, the doctrine of attractive efflu¬ 
via passing between bodies as the means 
of bringing them together, is in the last 
degree childish and unphilosophical ! It 
js wonderful how it could find a place 
pmong the grave disquisitions of rational 
beings; and yet, in the last and best mo¬ 
dern wark on Astionomv, in dur Astro¬ 
nomer Royal’s Translation of La Place, 
we find them discussing gravely this doe- 
trine of attractive effluvia, and actually 
speaking of the diliiculty of calculating 
their rate of motion for want of data, 
fomuled on new creations! ! ! 
I will apply and illustrate this prin¬ 
ciple of universal, pressure by examples: 
I. 
If there ivere only one mass of matter 
in the universe, the substratum wouhJ 
press it on every side alike; it WouKl 
remain in the same place, and could not 
move from the spot in which its existence 
commenced. It may be considered 
as' represented by the annexed ball, 
pressed on every side by powers extend¬ 
ing through infinite space. 
Corollary 1 . The immobility of 
such a mass supposes it to be of uniform 
density, and its parts balanced at its 
centre; or, in other words, that its mat he- 
vnitical centre, and its centre called, ihrtit 
of gravity, are the same. But if these dr> 
not balance, and if one s'lde of the 7 uas% 
has a peculiar arrangement of density 
greater than the other side, the whefr, 
by a uniform external, pressxire, is likely 
to be impelled into a rotatory motion. 
Corollary <2. Such is probably the 
arrangement of the planetary bodies, and 
SUCH THE CAUSE of their rotation on thei^ 
axes. The jiuid port of the, contents rf 
the earth, ifs perpetual oscillation, its 
excess cd'quantity over the solid parts, its 
unltorm opposition to the solid parts, (ail 
the land having water for its antipodes,) 
seem to indicate that the princiiile of 
fblation is a consequence of the peculiar 
disposition and adjustment of ihe compO'- 
nent pafts. 
ir. 
If tliere were two masses in the uni¬ 
verse, they would in like manner I'c 
pies‘-cd with equal force on every side, 
by tlie medium of infiiiite space, ex- 
CEUT OxNLA' IN T!IE LINE WHICH JOINS 
THEIR centres; uiul consequeiil!}’, as the 
pressure 
