6c>8 The Vehicle of Force. [October, 
the whole business clear — to themselves. Another class of 
reasoners, the advocates of what we may call the pressure 
and shelter theory of matter, have sought to get rid of these 
forces altogether, and explain them as results of momentum. 
But in doing so they have raised new difficulties, almost or 
quite as great as the old ones they have avoided. 
The true origin of force still remains a mystery, despite 
the theoretical attempts above mentioned. Yet the intense 
thought which has been expended on the effort to connect 
attraction and repulsion with matter, without satisfactory 
result, goes far to indicate that theorists have been clinging 
to a false conception, and wasting their powers on a stubborn 
effort to prove the impossible. There is, however, another 
point of view from which the question may be considered, 
which, strangely enough, seems to have never been attacked, 
and which I propose to consider in the present article. 
If we take it for granted that attraction and repulsion 
really exist, as forces distinct from the impaCt force of mo- 
mentum, certain necessary deductions follow. Not being 
motion they cannot be converted into motion, although long 
arguments have been made on the tacit assumption of such 
conversion. The quantity of motion in the universe is sup- 
posed to be unchangeable. Attraction and repulsion, not 
being motion, cannot add to nor take from this total quan- 
tity. And yet bodies, which were apparently at rest, start 
into visible motion under their influence, and our works on 
physical science are full of argument which amounts simply 
to a declaration that motion is created by attraction. For 
the theory of potential and aCtual force can be given no 
other interpretation. Disguise it as we may, potential force 
means simply possibility of motion. ACtual force means 
real motion. Thus, in the accepted theory, there lurks a 
distinct claim of the creation of motion, the possible being 
converted into the aCtual under the influence of attraction 
and repulsion. 
I have already dealt with this question in my article in 
the June number of the journal, on the modes of interchange 
between heat motion and mass motion. I have there sought 
to show that attraction and repulsion have not a creative — 
but simply a directive — power, and that all the motion which 
springs into visible existence had a previous invisible exist- 
ence, the vibrations of particles being readily convertible 
into the onward movements of masses, and the latter as 
readily transformable into heat vibration. 
We are thus enabled to somewhat simplify the question 
as follows : — There exists an unvarying quantity of matter, 
