TO THE GENESIS OF WORLDS. 



known substance, and that there are laws of nature by which, 

 through periods of time immensely long, the earth arid the 

 planets might have been rolled up from a gaseous nebula and 

 bowled off in their mighty revolutions, have just as much right 

 to say that it was so, as we have to say that the American forests 

 grew, or that the Triassic beds were deposited. 



Geology has proved that the earth, up to the primary rocks, 

 was once a molten mass. The crystalline structure of the un- 

 stratified rocks compels to this conclusion ; for minerals insoluble 

 in water can only become crystallized in large masses by cooling 

 from a state of fusion. If then the earth was once an incan- 

 descent globe of melted rocks for everything above the granite 

 beds must then have been in a state of vapor it is not un- 

 reasonable to suppose that it may have existed prior to that time 

 in a still more highly heated condition even volatilized and 

 diffused through space as rare and attenuated gases ; for this is 

 the condition which all matter assumes under sufficient degrees 

 of heat. In fact we must either suppose that the earth was 

 created as a fiery liquid globe, for which we have no warrant, or 

 we must follow back to the time when its vapors were scattered 

 in space, unreflecting and impenetrable to light when the earth 

 was " without form and void, and darkness was upon the face of 

 the deep." 



Let us start then with that condition of things which is now 

 very generally conceded must once have existed the diffusion 

 of matter in a nebulous form throughout all space. Calculations 

 easily made show that the nebula must have been of extreme 

 tenuity such that the few grains taken up on the point of a 

 knife-blade must have been expanded to fill several cubic miles. 

 A heat so powerful for we know of no other force which could 

 thus hold apart the atoms of matter would doubtless be suffi- 

 cient to resolve every known substance into its simplest elemen- 

 tary constituents, perhaps into a very few primordial elements ; 

 for chemists are far from being satisfied that they have arrived 

 at the ultimate forms of matter in their list of sixty-five ele- 

 ments. But however this may be, we know that the atoms, 

 whatever they were, must have been held so far apart that no 



