[27] We are aware that a certain class of thinkers regard all matter and combinations of matter as in some unexplained sense alive. We will discuss this doctrine in another place; meanwhile it must be understood that we do not here allude to this peculiar life, which from its very conception must exist as truly in a dead body as in a living one; what we are discussing at present is individual consciousness of the ordinary recognised type.
[28] As will be seen in [Chap. III.], the more important half of the realities of the physical world are forms of Energy, which cannot exist except when associated with Matter. We mention this merely in a footnote now, as we do not wish to diverge too far from our present line of argument.
[29] A very striking analogy to this will be found in [Chapter III.], where it is shown that energy of visible motion often disappears by transformation into the dormant or latent energy of position.
[30] See Essay on this subject by the Hon. Sir W. R. Grove, in his book on The Correlation of Physical Forces.
[31] See Contributions to Solar Physics, by De la Rue, Stewart, and Loewy.
[32] In [Chap. IV.] the reader will see that the only attempt to explain the mechanism of gravitation, which can be called even hopeful, does not give rigorously the law of the inverse square of the distance.
[33] ‘I hope all will be well. And, as for the gate you talk of, all the world knows that it is a great way off our country. I cannot think that any man in all our parts doth so much as know the way to it; nor need they matter whether they do or no, since we have, as you see, a fine, pleasant, green lane, that comes down from our country, the next way into the way.’
[34] This is discussed in [Chapter IV.] below.
[35] It is hardly needful to inform our readers that the word substance is used in this chapter in the ordinary sense.
[36] See Thomson and Tait’s Natural Philosophy, § 269; or Tait’s Thermodynamics, § 91.