Dr. T. Sterry Himfs Lecture. 357 



THE CHEMISTRY OF THE PRIMEVAL EAETH. 



A Lecture by Dr. T. Sterry Hunt, F.R.S., F.G.S., delivered at the Royal 

 Institution, London, on Friday Evening, Mat 31st, 1867.^ 



Mb. President, Ladies, and Gentlemen, — The subject of my 

 lecture this evening, as has been announced, is the Chemistry of the 

 Primeval Earth. The natural history of the earth, to which we 

 give the name of " Geology," is necessarily a very complex science, 

 including, as it does, the concrete sciences of Mineralogy, of Botany, 

 and of Zoology, and the abstract sciences of Chemistry and of 

 physics, not to speak of others. These sciences, and especially 

 chemistry and physics, have a very important relation with regard 

 to the whole process of development of our earth, and have, from 

 the very first time, exercised a most important relation with regard 

 to all its changes. And we have lately learned, from more extensive 

 study, that these chemical laws apply not only to terrestrial, but to 

 extra-terrestrial matter. Recent investigations show us in fact, as 

 might have been presumed, that all the other bodies of our solar 

 system, and bodies even of other systems, revolving around other 

 suns, have essentially the same chemical composition as our own 

 planet. The spectroscope, that marvellous instrument in the hands 

 of modern investigators, has thrown a light upon the composition of 

 the farthest bodies of the universe, and has made clear many points 

 which the telescope had not been able clearly to decipher. It has 

 shown us, as it were, matter in all its different stages, and has en- 

 abled us to trace the great processes of the condensation and the 

 formation, so to speak, of worlds. It is, as you are aware, long 

 since Herschel speculated upon the nebulous matter which seemed 

 to be diffused in different parts of space. Some of these nebulae Lord 

 Eosse and others were able, with their great telescopes, to resolve, and 

 to show that they were really composed of stars ; and thence there 

 came a doubt whether there were really such masses of nebidous 

 matter diffused as had been hitherto maintained, but the spectroscope 

 has placed that beyond a doubt, and has enabled us to see in the 

 bodies in the heavens above, not only planets like our own earth 

 shining by reflected light, and other bodies like the sun, consisting of 

 luminous and apparently solid particles, but also others still — true 

 nebulous masses, that is to say, luminous gaseous matter, — these 

 three forms representing, as we may suppose, three distinct phases 

 of the consolidation or the condensation of the first primal matter 

 from which our earth, as well as all the other bodies of the solar 

 system, would seem to have originated. 



This nebulous matter we conclude to be intensely heated — so in- 

 tensely heated as to be completely gaseous, and, in fact, to owe this 

 gaseous form to its intensely elevated temperature ; being, however, 

 comparatively feebly luminous when we contrast it with the solid 



' Being a fuU report taken down verbatim in shorthand, and now printed for the 

 first time. 



