76 THE ORIGIN OF LIFE 



assurance ; since in truth experiment and knowledge 

 teach it, that, whilst life and death are only one so 

 far as our experience goes, the process of the universe 

 is continuous and complete. 



It will be evident from these few remarks that our 

 object is to indicate that the molecular processes 

 which manifest themselves by luminosity are of the 

 nature of a building up and breaking down of groups 

 of molecules, so that the analogy with vital processes, 

 though not enough to identify the two, is yet more 

 than plausible. 



Still, the barrier between the living and the dead, 

 if by the living we mean the organised cell which to 

 the biologist is the ultimate unit of living things, 

 this barrier, we must admit, remains where it was 

 before : although the fact that the natural cell ap- 

 parently cannot be produced artificially from other 

 and simpler forms of " unstable " or living matter 

 does not draw a sharp distinction between them, 

 any more than that radium cannot be synthesised 

 from its constituent products is a proof or even a 

 reason for regarding it as belonging to an entirely 

 different branch of science from those which deal 

 with the simpler elements. 



The fact, we say, that a bacterium cannot be produced 

 artificially, because it is too highly organised, wUl 

 not prevent the hope of producing the next best 

 thing to it, a molecular aggregation of a highly 

 complex matter, an organic or colloidal body which 

 possesses the (n—l) properties of the n properties of 

 the living bacillus — things which would grow and 



