The Chemistry of the Primeval Earth. 359 



result — the combination of these elements ; and thus, literally, to use 

 Milton's line, " frost would be found to perform the effect of fire." 

 Now, it seems from still later investigations by Deville and by others, 

 that this great law of indifference of bodies when intensely heated 

 is a universal law, and that this priuciple, which Deville calls 

 "dissociation," probably extends to all matter. All the substances 

 that we know would probably, at a sufficiently high temperature, be 

 dissociated : that is to say, the various elements which make up the 

 earth — which make up any body — when in this state of intense 

 ignition would be uncombined, and, moreover, would all be capable 

 of being reduced to the state of vapor — to the state of gas ; and this 

 we must conceive to be the real condition of the matter which 

 forms the sun. 



Now what must be the process going on at the surface of such an 

 immense mass of matter, intensely heated, but by the very fact that 

 it is gaseous, but feebly luminous ? You are well aware that a 

 hydrogen flame without any solid matter in it, though giving a very 

 high temperature, emits almost no light whatever. At the surface 

 of this enormous globe, the sun, a process of cooling would be going 

 on ; and there such bodies as at the still very high temperature 

 were capable of uniting — to form oxides, let us say — would be pre- 

 cipitated, and would form a sort of mass or cloud suspended in the 

 still dissociated vapours, and would then give off light and become 

 intensely luminous, as such solid particles necessarily are, and would 

 thus give rise to a brilliant light, and would also radiate the sun's 

 heat. Hence we suppose that at the surface of the sun, and at the 

 surface only, there is this process of condensation going on. This 

 hypothesis, lately put forward, has, I am aware, been opposed ; but 

 it does not seem to me that the arguments which have been brought 

 against it are valid, and I cannot but think, from the present state 

 of our knowledge, that it affords us something like a correct idea of 

 the nature of the action which is going on at the sun's surface. 



But you will ask what all this has to do with our earth ? Very 

 much, and for this reason : the almost universally accepted hypo- 

 thesis with regard to the origin of our solar system, not to speak of 

 other systems, is that the different bodies of our system — the sun 

 and the planets which compose it — have been evolved out of a 

 common nebulous mass. 



Now, whether we admit that nebulous mass in rotating to have 

 thrown off successive bands, which bands have been broken up and 

 agglomerated into worlds, or whether, with Chacornac and some 

 others, we suppose that in the midst of this great nebulous mass a 

 process of concretion went on by which an enormous ball of 

 vaporous matter resolved itself somewhat as you may see, a white 

 cloudy mass, at times breaking up and resolving into smaller masses 

 of clouds, — I say, whether you adopt one or the other notion with 

 regard to the breaking up of this great nebulous mass, and the 

 formation from it of sun and of planets, you come to the conclusion 

 that our earth must at one time have been a portion of such a nebu- 

 lous mass as is the sun at the present day : in other words, it must 



