402 
surprise some persons to find that what I quote from him is 
in accordance with my own “ heretical” views! Well,, that 
distinguished scientific author, in the first edition of his cele- 
brated work on The Correlation of Physical Forces (1846), thus 
expressed himself : — 
u Inertia appears to me to he a static condition of the force of gravitation, 
or, in other words, resistance to motion [he means force] occasioned by the 
force of gravitation. Without gravitation I cannot conceive, inertia .” 
And in the second edition of the same work, published in 
1850, 1 find the following passage: — “ The phenomenal effects 
of gravitation and inertia, if there he such a force as inertia , 
being motion and resistance to motion,” &c. But I regret to 
be obliged to add that I cannot trace any corresponding 
passages in the last edition of Mr. Grove's book, published 
in 1862, though I am glad to find he does not shrink 
from repeating in it his reasoning against Black's theory of 
“ latent heat,'' and opposes the more modern notion of 
“invisible light,'' as to both of which scientific dogmas I, too, 
have ventured to be a thorough “ heretic.'' Why Mr. Grove 
now sinks his opposition to the self-contradictory notion of 
“ such a force as inertia,” it is not for me to say. For myself, 
I continue, profanely, without the least reverence for Vis 
Inertia e, in both senses of the latter word. 
36. But more popular authors also enlighten the public 
with their views of Newtonian dogmas. A really brilliant 
writer, in an article on “ Force,'' in the Cornhill Magazine for 
1861, put forth the following, not, indeed (he said), as the 
“ common-sense " view of things, but as “ that which arises 
from the thoughtful tracing of their real connection,'' or the 
scientific view: — 
“ All actions in nature are two equal and opposite actions. It is a law 
with no exception, nor possibility of exception. Nor is any change, any 
seeming origination or ending of an action, rightly apprehended till it is 
seen thus in absolute interlinking with its fellow. We are familiar with 
this principle in some simple instances, but the demand is that we should be 
sure of it in all. The very spirit of science consists in the confidence with 
which it is grasped, and applied to all cases, however vast beyond the reach of 
our observation, or complex beyond our power to unravel , however long the 
completion of the process may be deferred.” 
This might well be called, in my opinion, the third law of 
motion travestied, or action and reaction run mad ! And yet 
I fear this writer's views are not altogether uncommon in our 
day. He somehow connects this “ law " with the alternate 
