23 
dent, that tfttere is no way of sustaining it by argument. I leave to those 
who maintain the indestructibility of matter, the task which their position 
imposes upon them of proving that it was not created.” 
This, in point of fact, appears to me to be the gist of the paper, and in this, 
I am sure I am entirely in accord with the author. But there are several 
points in the argument about which I should like to have asked him for 
some information. In the same page (sec. 24) he says — 
k According to the third hypothesis, all active force is resident in the 
It must be apparent to any mind, that this ether has an altogether hypothetical 
existence. We know nothing about it. We never can see, feel, test, or 
weigh it. In fact, we have no evidence of its existence beyond the necessity 
for the existence of some exceedingly elastic matter, to convey from the sun, 
the vibrations which constitute light and heat, to this earth. We know that 
some highly-elastic matter must exist and fill the whole of space between us 
and the sun, in order to convey the light and heat so essential to the de- 
velopment of life on the earth. But beyond this we know nothing about it. 
In the next page the author says — 
“ It must be by the same medium that force is exerted, when of our own 
will, under conditions and limitations of organization, we move our limbs, or 
set in motion any extraneous body. But in this case our own consciousness 
tells us that the exertion of the force is a mental or spiritual act.” 
Now, it is quite clear to my mind that the mental act, that is, the act of voli- 
tion, is an antecedent cause to the exertion of the force. The exertion of 
the force is the contraction of the muscular fibres, the muscular fibres that 
move the arm, for instance ; the contraction of these fibres is the immediate 
agent in the exertion of the force. This certainly is a material, and not a 
spiritual, act. The antecedent volition is the spiritual act ; but it appears to 
me the exertion of the force is not a spiritual act. 
Mr. Challis. — The Professor goes beyond the muscles, and speaks of that 
which puts them in action. 
The Chairman. — He does not say it in so many words, but I conclude 
from section 4, that he considers — and in this I entirely agree with him 
— that sound, as well as light and heat, have no objective existence ; 
that sound, light, and heat are entirely subjective sensations, and that 
all that exists objectively is the vibratory motions. In sec. 10, with regard 
to the laws he propounds, the first is, “ All matter that we are cognizant 
of by our senses, is composed of discrete atoms.” The second is, “ An 
atom is a very small sphere, inert, movable, and of finite and invariable 
magnitude.” Now, it appears to me that the assumption that the form of 
an atom is a sphere, rather involves more difficulties than it obviates, 
because by the laws of crystallization, the form of crystals necessitates that 
there should be unequal attractive forces between the molecules and the 
substance of the crystal, one or two, sometimes three unequal — sometimes in 
