103 
our information as to the Visible Universe, so far as we know 
anything of it? (p. 97). 
The doctrine of Lucretius is here described and dismissed; 
partly as metaphysical, (which our authors may take 
to mean speculative or tanciiui — that we suppose is theory of lu- 
the vulgar notion), and partly as superseded (p. 102). cretms - 
The doctrine of Boscovitch is next stated, and it is said 
that it was somewhat supported by Faraday. This wholly 
denied the Lucretian atom, and all atoms, getting central force 
rid of substance in favour of central force, “residing in theory of bos- . 
nothing, but related to everything ” (p. 102). This siding in 
our authors also dismiss as an “ over refinement of nothmg) - 
speculation ” ; for it does not provide for “ inertia,” at all. 
A third speculation as to the intimate nature of Matter, 
would regard it as non-atomic, but infinitely divi- Non-atomic 
sible, or the utter reverse of atomic. This is scarcely theor y- 
reconcilable, however, with “ gravitation-attraction,” and 
might at length dispense with molecular forces and chemical 
affinities. Our authors think it involves too great a scientific 
confusion. 
Then there is the vortex-atom theory of Sir W. Thomson, 
which supposed matter to be the rotating portions 
of a perfect fluid filling all space. On this theory thIo^ eX o"f at s?r 
our authors see difficulties to arise ; and they do not w ‘ Thomson - 
make up their minds (p. 104). 
22. They say they cannot conceal, that their ideas of what 
Matter is, (though unmetaphysical), “are hazy” (pp. 104 and 
105). Helmholtz's investigations rather incline them to 
vortex-atoms. But the “ perfect fluid theory ” would imply 
Creation to impart the rotatory motion in it; and so “may 
only shift the difficulty a little farther back.” And it does not 
account for the inertia of matter, any more than the other 
three theories; — (or it may “refine away the whole idea of 
matter”) — which the mind seems to require! 
There is an attempt to account for inertia, and for gravitation, 
in the theory of Le Sage, (partly adopted with modi- Theory of he 
fications by Sir Wm. Thomson), as to infinitely Sa £ e - 
small corpuscles, ultra-mundane or from the unseen world, 
filling space (p. 164) ; but this theory would modify the 
present doctrine of kinetic and potential energy, on which 
we have proceeded (p. 110) ; as the third theory also clashed 
with gravitation; and the second with inertia. 
An eftort has been made to connect gravitation Of gravita- 
with that luminiferous ether, (which is a great re- ^iferois' 
finementon gross matter), which is the hypothetical cthcr - 
