46 THE BIOLOGICAL APPROACH 



that they are formed mainly from the elements C, O, H and N. 

 Several of these compounds, particularly the proteins, form very 

 large molecules of an intricate structure. The structure of these large 

 organic molecules is now in the process of being unravelled, and 

 papers relating to this study are common in scientific and popular 

 literature. We need not go into this matter here, if we only retain 

 from these biological studies of our present life the fact that most 

 natural organic compounds arc formed by large and complicated 

 molecules. 



IMPOSSIBILITY OF NATURAL SYNTHESIS OF ORGANIC COMPOUNDS 

 IN THE PRESENT ATMOSPHERE 



This fact is of decisive importance for an evaluation of the possibil- 

 ities of the origin of life, for the synthesis by natural inorganic pro- 

 cesses of such large, complicated molecules happens to be wellnigh 

 impossible under present environmental circumstances. Under our 

 present conditions of temperature, light, composition of the atmos- 

 phere and the hydrosphere, only much smaller molecules formed 

 from the same elements are stable, whilst the larger organic com- 

 pounds are unstable. Even if, by some extremely unlikely coincidence, 

 such an organic molecule had formed, it would be destroyed again 

 immediately, cither by inorganic oxidation processes, or by organic 

 oxidation, such as rotting. So these large organic molecules cannot 

 at present exist on their own, inorganically, without any relation 

 whatsoever to living organisms. They cannot be formed regularly, 

 or even rarely, in natural inorganic chemistry and even if this would 

 be possible, they are liable to immediate destruction. 



The statements above do, of course, no more than paraphrase the 

 wide gulf that at present exists in nature between organic and in- 

 organic chemical compounds, — a gulf so wide that until it had 

 been bridged by the synthesis of ureum in 1828, it seemed as if even 

 man-made chemistry would forever be unable to produce these 

 organic molecules, a process which seemed reserved exclusively to 

 the metabolism of living things. 



So we must realise that natural organic compounds cannot, by 

 any means, be formed in nature now, except through processes 

 occurring in living matter already in existence. Under present condi- 

 tions, it follows that the origin of life from inorganic beginnings is 



