forces. But the ether must he intensely elastic ; and that elasticity cannot 
be supposed to proceed from any kinetic arrrangement, for that ^vould require 
the atoms of the ether, themselves, to be elastic ; and we have no choice left 
us, except we adopt the hypothesis to which Challis refers, of an infinite suc- 
cession of ethers, each constituting the elasticity of its predecessor, but to 
suppose these atoms, the ultimate elements of all material forces, to be 
endowed by the Almighty with repulsive power when He said, “ Let light 
be ! Thus, in Dr. Kobinson’s vfiew, the only tenable supposition is that 
with which the passage just cited concludes, namely, that the atoms of the 
ether have been endowed with repulsive power by the Creator. Professor 
Challis, in the remarks which he did me the honour to make on my paper of 
last year, states that he at one time inclined to the theory of successive ethei-s, 
but has since abandoned it. The theory finally adopted by him may be 
found, given in his own words, in p. 79 of the number of the journal of the 
Victoria Institute for March, 1881. On referring to that place it will be 
seen that he does not admit that the etherial atoms are endowed with 
repulsive forces. He holds that after having arrived (as he has done by his 
mathematical researches) at the conclusion that the pressure of the ether is 
proportional to its density — in other words, that it is equal to its density 
multiplied by an ever-constant factor — we have taken all the material agency 
into account ; and that the constancy of that factor — the only thing not 
accounted for by such agency — owes its origin to non-material agency, i.e., 
Mind : and that this is quite in accordance with the weU-known fact that 
while sound, light, &c., are, in one point of view, material conditions, our 
jpercejption of them can only be accounted for by admitting that there must 
be a non-material or spiritual agency also. 
Again, Dr. Kobinson says : — “ With respect to the Conservation of Energy 
it seems to me that the statements about it have not been weighed with suffi- 
cient care. It is by no means generally true that one form of energy can 
be immediately transformed into another. For instance, every writer or 
lecturer nowadays talks of magnetism being converted into electricity and 
vim versa ; but this is not the fact. A magnet may stay beside a wire foi’ 
ever without producing any signs of electricity ; but if it be moved to or from 
the wire a current appears, the intensity of which is found, even on the 
largest scale, to be in exact proportion to the moving power expended. 
Again, chemical affinity can produce electricity, light, and heat ; but not 
magnetism. And even in this case motion is necessary to bring the com- 
bining bodies into contact ; and as to the greatest and most universal of all 
forces — gravity — it, as far as vre know, cannot be transformed into any other 
form of energy. . . . These and similar matters make me think that in 
the transformation of forces we have not got to the bottom of the matter ; 
and it must be kept in mind that very often the ultimate agent in the trans- 
formation is human will, — for example, setting an electric generator in motion 
or charging a battery. And this fact might lead us to a far wider and more 
elevated conception of the universal influence of the highest of all wills (that 
of the Creator), as connected with the absolute existence of energy itself.” 
Unless I could boast of such an acquaintance with the whole range of the 
physical sciences as Doctor Kobinson himself possesses, I should consider 
myself presumptuous were I to offer any opinion on these views in detail. 
But I think it will be at least admitted that he has brought forward some 
good reasons for refusing to look upon the doctrine of Conservation of 
Energy as having become fully and finally established. 
