186 REV. A. IRVING, D.SC., B.A., ON 
III. Toe Souar EArtu. 
For a long time (see my previous paper to this Society) it 
was easy to point to a “manifest absurdity” in the Mosaic 
Cosmogony, since that represents the appearance of light at the 
first stage, while the celestial luminaries are represented as not 
appearing before the fourth. Such shallow criticism is now 
seen to be based, not on knowledge but on ignorance, since the 
fuller comparative study of the Solar System in recent years, 
and the extension backwards in time of the physical history of 
this globe,in the light of the great law of Dissipation of Energy 
and all that it involves, has given us a new mental perspective. 
The results of investigation on such lines have made it 
practically certain that our planet, in common with other 
members of the system, has passed through what Zollner years 
ago called the “solar phase” of its history; and the results of 
the application of telescopic photography to astronomy have 
revealed things to us in the “ spiral nebulz,” which confirm my 
suggestion of more than twenty years ago as to the nucleate 
oryin of the planets.* This hypothesis in a somewhat modified 
form has been more recently adopted by Messrs. Chamberlin 
and Salisbury in their great text book of Geology. In other 
words this dark ball, which now revolves round the sun, was in 
the remote past self-luminous, as the central orb of the system 
is to-day. Assuming that the elements appeared in the nebula 
in a state of elemental dissociation, as they appear to exist in 
the tails of the comets,+ then combustion on an inconceivably 
enormous scale would go on during that solar stage to produce 
not only steam (H,O), but also the oxides of the metals, of 
silicon and of carbon, which together form well over 90 per 
cent. of the constituent materials of the rocks, which make up 
the present lithosphere of the planet. If it did not involve the 
use of language too technical for the present occasion it would 
not be difficult to indicate roughly from the teaching of the 
higher chemistry the order in which such oxidation probably 
proceeded; and I go so far as to assert that we should arrive: 
at results which would render the assumptions which underlie 
the theory as to the salinity of the hydrosphere propounded 
* See my Chemical and Physical Studies, ete. (Longmans, 1899),. 
pp. 22-24, also my previous paper, “ Evolutiovary Law, etc.,” § IV, and 
Trans. Vict. /nst., vol. xxxvii, pp. 210 ff.; also the “Note” at the end 
of this section. 
t Cf. letter to the Zimes by Sir Robert 8. Ball, F.R.S. (Feb. 10th, 1910). 
