COSMOGONY. 



The science of cosmogony treats of the history of creation. 



Geology comprises that later portion of the history which is within 

 the range of direct investigation, beginning with the rock-covered 

 globe, and gathering only a few hints as to a previous state of igneous 

 fluidity. 



Through Astronomy, our knowledge of this earlier state becomes 

 less doubtful, and we even discover evidence of a period still more re- 

 mote. Ascertaining thence that the sun of our system is in intense 

 ignition, that the moon, the earth's satellite, was once a globe of fire, 

 but is now cooled and covered with extinct craters, and that space is 

 filled with burning suns, — and learning also from physical science 

 that all heated bodies in space must have been losing heat through 

 past time, the smallest most rapidly, — we safely conclude that the 

 earth has passed through a stage of igneous fluidity. 



Again, as to the remoter period : the forms of the nebulae and of 

 other starry systems in the heavens, and the relations which subsist 

 between the spheres in our own system, have been found to be such as 

 would have resulted if the whole universe had been evolved from an 

 original nebula, or gaseous fluid. It is not necessary for the strength 

 of this argument that any portion of the primal nebula should exist 

 now, at this late period in the history of the universe ; it is only what 

 might have been expected, that the so-called nebulas of the present 

 heavens should be turning out to be clusters of stars. If, then, this 

 nebular theory be true, the universe has been developed from a primal 

 unit ; and the earth is one of the individual orbs produced in the 

 course of its evolution. The history of the universe is in kind like 

 that which has been deciphered with regard to the earth : it only car- 

 ries the action of physical forces, under a sustaining and directing 

 hand, farther back in time. 



The science of Chemistry also is aiding in the study of the earth's 

 earliest development, and is preparing itself to write a history of the 

 various changes which should have taken place among the elements, 

 from the first commencement of combination to the formation of the 

 solid crust of our globe. 



It is not proposed to enter in this place into either chemical or as- 



