362 Dr. T. Sterry Hunt's Lecture— 



which is in the form of coal would be burned and converted into 

 carbonic acid. All the siliceous matters which make up the earth's 

 crust, the quartz and the sandstones, would act upon the carbonates 

 of lime and expel all the carbonic acid. The waters of the sea, 

 volatilized, would leave a residue of salt and of gypsum behind 

 them ; and these materials again acted upon by the excess of sili- 

 ceous matters in the crust, in the presence of water, would expel 

 all the chlorine in the form of hydrochloric acid. All the sulphur 

 would be diffused in the atmosphere in the form of sulphurous acid ; 

 and eventually all the lime, the magnesia, the soda, the potash, and 

 the metallic bases would be combined with alumina and silica in a 

 great fluid magma whose composition would be, perhaps, more like 

 the slag of some of our iron furnaces in its composition than any- 

 thing else we know ; and the slow cooling of them would probably 

 develop various crystalline compounds. The cooling of such a mass 

 at length would render it somewhat viscid ; and then, as I mentioned, 

 inasmuch as the solid rock is always denser than the liquid, you would 

 have irregular shrinkings and corrugations of the surface, so that the 

 first cool surface of the globe would be a scoriaceous slaggy mass, 

 as I conceive, — with exceedingly irregular outlines of hill and valley, 

 — a curiously depressed and corrugated surface, — perhaps such a 

 surface as the moon presents to us through a telescope, — perhaps 

 such a surface as we observe on a mass of fused silver after it has 

 come out of the furnace and is giving off the gases which it has 

 absorbed, — and it is very probable that gases may be absorbed 

 during the cooling of this scoriaceous mass. 



But then let us ask what is the composition of that atmosphere. 

 In that atmosphere we should have the whole of the carbon in the 

 form of carbonic acid; the whole of the chlorine in the form of 

 hydrochloric acid ; the sulphur as sulphurous acid ; and we should, 

 moreover, have nitrogen and probably an excess of oxygen. This 

 great accumulation of gases, and of hydrogen in the form of watery 

 vapor, would give rise to an atmosphere of enormous density. The 

 atmospheric column at that time must probably have weighed upon 

 the earth's surface with a weight seven times that of our atmosphere 

 at the present day, and the cooling of this crust would have then 

 gone on very, very slowly. Heat would radiate with extreme 

 difficulty from this mass, and ages would take place probably before 

 the cooling came on to such a point as to admit of condensation. 

 But just let us conceive that under this high column, this great 

 pressure, condensation of water would take place at a very much 

 higher temperature than it does under our present atmospheric 

 column. That water might remain in a liquid state on the earth's 

 surface at temperatures, perhaps, of 300 or 400 degrees ; — this 

 would depend upon the unknown height of this great barometrical 

 column, of which we have not sufficient data to determine the exact 

 weight. Then this first water coming down, moistening the surface 

 of this crust, would be intensely impregnated with acids, especially 

 hydrochloric acid. We all know from chemical investigation that 

 this rocky slaggy mass would be readily attacked on the surface by 



