292 
intimately mingled, and by which it has been chemically affected in being so 
mingled. There is, beyond all question, a substance in the powder which 
is not in the cake, as truly as there is one in proper gunpowder which is 
not in that which lacks sulphur. 
The two pieces of iron — one magnetized and the other not — afford an 
illustration of a truth which Mr. Warington does not seem to have appre- 
hended. The magnetic current is passing through the magnetized iron, as 
the current of heat passes through the proper gunpowder, when a red-hot wire 
is applied to it. The magnetic “affection” of this iron is the result of its 
having had the magnetic current introduced to it ; just as the explosion of 
the gunpowder is the result of introducing the “ affection ” of heat from the 
wire. The iron which is not magnetized is simply a piece of that metal 
which has not yet been placed so as to receive the magnetic stream. It is 
like a portion of good gunpowder which has not yet been fired. It is con- 
sequently not in that state of magnetic agitation in which it would attract 
other pieces. But the instant it has the magnetic current introduced, it is 
affected, and affects in turn, like the other. We therefore argue that the 
substances are alike, inasmuch as they are both affected equally and made 
to affect other masses by that movement which we call magnetism. If two 
bars are placed equally in a magnetic current, and the one is magnetized, 
while the other is not, we inevitably conclude that there is something in the 
one which is not in the other. My argument is therefore perfect. 
As to Mr. Warington’s defence of Professor Grove’s confounding “ force ” 
and “ motion,” I have only to say that I think it is a hasty argument on 
behalf of loosely employed language. I certainly do not admit that “ force 
is nothing more than motion,” any more than I admit that “ cause ” is 
nothing more than “ effect ; ” and I must contend that so long as phi- 
losophers are content with that confusion of thought, and of words which 
mix up force with motion, cause with effect, and law with observed 
uniformity, they are not likely to enjoy the truth. But I have said enough 
as to this in the paper itself. 
It is, i perhaps, more important to speak of Mr. Warington’s idea that 
mind is only a directive cause. His own illustration of “ the gas ” ought to 
light him out of the notion. Because the pipe will not light when there is 
no gas in it— that is, because the gas will not light where it is not; 
because the gas must exist in order to be in a state of combustion— he argues 
that when there is gas in the pipe it is not the person who applies the match 
to it> who is the cause of the light ! He says, too, that the “ combustion is 
the cause of the flame ” ! I humbly think that the flame consists of the 
gas and a portion of the atmospheric air in a state of combustion. The mere 
state of a thing cannot be the cause of that thing ; nor can such state be 
its own cause. This state of combustion is communicated when a match in 
the same state is brought near enough to the combustible substance, as a 
ball in motion communicates its motion to a ball at rest when the one hits 
the other. It is certainly inaccurate to say that the combustion of the gas 
is the “ cause ” of the flame, even as Mr. Warington would have us to use 
