LIFE AND THE COSMOS 309 



hand, is no concern of the scientist. What- 

 ever else it may achieve, mechanism can never 

 explain, cannot even face the problem of the 

 existence of matter and energy. Within the 

 world of science these are conserved ; only 

 outside that world can they have originated 

 or not originated. As for the existence of 

 life, in spite of our utter ignorance, it must 

 be admitted that a half century has greatly 

 diminished the number of substantial biolo- 

 gists who really look forward to its scientific 

 explanation, and the greatest chemists have 

 ever shared such a view. Liebig is reported 

 by Lord Kelvin to have replied to the ques- 

 tion whether he believed that a leaf or a flower 

 could be formed or could grow by chemical 

 forces, "I would more readily believe that a 

 book on chemistry or on botany could grow 

 out of dead matter. " 1 Darwin, too, once 

 said, "It is mere rubbish thinking at present 

 of the origin of life; one might as well think 

 of the origin of matter." 2 Since Liebig's 

 day the chemical organization of the cell has 

 become in scientific knowledge vastly more 

 complex than it was before, and I know of no 

 biological chemist to whom the spontaneous, 



1 Lord Kelvin, "On the Dissipation of Energy," Popular 

 Lectures, Vol. Ill, p. 464. 



2 Merz, Vol. II, p. 406. 



