126 REV. C. GODFREY ASHWIN, M.A. 
neither change nor pass away, but, on the contrary, form fixed 
centres about which other truths aggregate by a natural 
affinity.” * 
Every one must admit the truth of this conclusion as regards 
jacts, and no one could give a more earnest warning’ respecting 
the theories, that vary from year to year, than he has done in 
these words: “ The army of liberal thought is at present in 
very loose order, and many a spirited free-thinker makes use 
of his freedom mainly to vent nonsense.” + 
This must be borne in mind in considering both the 
accepted facts of science and some of the more prominent and 
plausible speculations. The following are generally admitted 
as facts :— 
1. The immense duration of the earth’s history. 
2. The gradual formation of the earth’s crust by processes 
still in operation. 
3. The homogeneous character of the materials of which 
sun, moon, and planets, including our own earth, are com- 
posed. 
4, he uniformity and inviolability of the laws of nature. 
5. The vast duration of human life on earth. 
6. The indestructibility of matter. 
It is true that some would relegate the last two of these 
from the category of proved facts to that of prominent and 
plausible speculation. For, the evidence of the extreme 
antiquity of man does not appear conclusive to all. And the 
theory that matter may be merely a form of vortical motion of 
a pure fluid which fills the universe is supposed by some to 
modify former conclusions as to the indestructibility of matter. } 
Amongst the plausible speculations not yet accepted as 
facts are,— 
(a.) The evolution of higher from lower forms of organic 
life, including the animal and man. 
* Lay Sermons, p. 124. 1.5 ps 69: 
t Supposing the Kinetic theory of the structure of matter be proved, and 
avery superficial knowledge of the theory is deeply interesting and highly 
suggestive, how far does it affect the question of the destructibility or inde- 
structibility of matter? Professor Tait says: “If we adopt Sir William 
Thomson’s notion of a perfect fluid filling infinite space, all vortex rings, 
and therefore, according to Sir W. Thomson, all atoms of matter, must 
necessarily be endless ; that is, must have their ends finally united together. 
Secondly, Helmholtz shows that such a ring is indivisible ; in that sense ‘a 
vortex ring’ is literally an atom. Therefore, if any portions of the perfect 
fluid have vortex motion communicated to them, they will remain for ever 
