AGE OF THE EARTH AS AN ABODE FITTED FOR LIFE. 357 



twenty or thirty million years for the sun to be anything nearly as 

 warm as he is at present. If the consolidation of the earth was fin- 

 ished twenty or twenty-five million years ago the sun was probably 

 ready — though probably not then quite so warm as at present, yet 

 warm enough to support some kind of vegetable and animal life on the 

 earth. 



44. My task has been rigorously confined to what, humanly speak- 

 ing, we may call the fortuitous concourse of atoms in the preparation 

 of the earth as an abode fitted for life, excei)t in so far as I have 

 referred to vegetation, as possibly having been concerned in the prep- 

 aration of an atmosphere suitable for animal life as we now have it. 

 Mathematics and dynamics fail us when we contemplate the earth, 

 fitted for life but lifeless, and try to imagine the commencement of life 

 upon it. This certainly did not take place by any action of chemistry, 

 or electricity, or crystalline grouping of molecules under the iniiuence 

 of force, or by any possible kind of fortuitous concourse of atoms. We 

 must pause, face to face with the mystery and miracle of the creation 

 of living creatures. 



