THE CONSTITUTION OF BODY. 
541 
tween two discordant physical hypotheses, which yet may possibly be brought 
to accord, but between a physical theory of actual, finite, physical atoms, and a 
metaphysical theory of ideal, infinitely small metaphysical atoms. If we desire 
to deal with actualities, then, since no kind of infinity can be predicated of any¬ 
thing finite, we are precluded from assuming for body component parts, which 
shall be infinitely small. Moreover, physical atoms cannot possibly be conceived 
otherwise than as finites. On the other hand, when, for purposes of explana¬ 
tion or elucidation we turn to the theoretical aspect of the case, then we are 
driven to have recourse to a theory of infinites. In this point of view, the 
atom is the precise analogue of the geometrical point, and for that very reason 
is purely ideal. Both theories are necessary, though they are incapable of 
being fused and harmonized into one. It is the former, as I venture to think, 
that must always be the constitutive theory of chemistry, while the latter must 
be content to be put to regulative uses. 
When dealing with absolute infinites, we cannot ascribe to them anything re¬ 
lative ; neither weight, nor magnitude, nor any other physical property; not 
even though we concede, as we very well may, that infinite smallness is not 
absolutely nothing, but only a vanishing point. 
§ 5. It is much to be wished that the nature of the case had permitted the 
author of this interesting paper to place before us his views as to the reconcilia¬ 
tion of the two theories more distinctly and precisely. As it is, we are precluded 
from judging whether these view's are, or are not, more in harmony with the 
general plan of nature than any other views. But, certainly, the idea of infi¬ 
nite divisibility (i. e. of infinites) can never be excluded from consideration, 
either by chemistry or by physics. 
The term, “ imponderable agents,” is a most objectionable form of expression, 
inasmuch as it implies that, the forces so termed are still matter, though matter 
of a most ethereal kind; and as long as such a name continues to be used, the 
opinion will still survive, that the physical forces are material substances of ex¬ 
ceeding tenuity. 
Is it not setting up a man of straw, to raise a difficulty as to the action of in¬ 
finites (i. e. of forces) upon finites? What is that motion, into which the paper 
■we are examining resolves all the physical forces, but an action of infinites upon 
finites ? 
§ 6. The conclusions arrived at in this section are, “heat, light, electricity, 
magnetism, are, then, motion and again, “ change, we may henceforth believe, 
is motion.” Then, since any number of things which are severally equal to a 
given thing, are therefore equal to each other, heat, light, electricity and mag¬ 
netism, together with change, are convertible terms, and mean, each and all of 
them, one and the same thing ! Naturally, we all understand the writer’s mean¬ 
ing to be that, these forces involve, or are accompanied by, or issue in, motion. 
But, to say that they are motion, that because a, 6, c, d, aud e are always asso¬ 
ciated with ?«, that therefore they are m, is a logical sin of the deepest dye. Such 
a pseudo-generalization, if acquiesced in, teaches nothing, leads to nothing, and 
shuts the door on further inquiry. The hollowness of such loose attempts to 
generalize is further evident, when we observe that, change is a result of motion ; 
while heat, light, etc., are its causes. Nor, is the fact, that two forces are mu¬ 
tually convertible, any evidence of their identity, though it may afford a pre¬ 
sumption of the identity of their origin. It is not that, e. g. electricity^mag¬ 
netism, but, that electricity-1-a:, or —magnetism ; and it is precisely the 
values of these several z 1 s and y s, which thus differentiate the two pairs of forces, 
light and heat, from electricity and magnetism, and again, the respective mem¬ 
bers of either pair from each other, that science just now most earnestly desires 
to discover. 
The suggestion of Professor Graham that, the different so-called elementary 
