PHYSICAL CONDITIONS AT BEGINNING OF LIFE 585 



2. How did these amino acids polymerise, or unite among 

 themselves, to the formation of complex polypeptides or 

 proteins, and how did these in turn unite with phosphoric 

 acid to form nucleo-proteins ? 



3. In what way, and in what sort of a medium, did these 

 nuclein compounds acquire the capacity of auto-synthesis, and 

 under what conditions would the products thus automatically 

 formed unite in loose colloidal union to ultra-microscopic 

 granules and hen microzymes, chromosomes, spheroplasts, and 

 their like ? 



4. Under what physico-chemical conditions were these living 

 granules associated to form the first simple cells ? 



Assuming, as we are justified by a multitude of inferences 

 from its present-day reactions, that living substance was not 

 in principle different at its beginning from what it is now, 

 we may consider what conditions are implied from this con- 

 ception of the problem. 



Formaldehyde, together with a variety of similar substances, 

 as for example formic acid, has recently been synthesised by 

 W. Lob 1 by exposing a mixture of carbon dioxide and water 

 vapour to the action of the silent electric discharge. This 

 reaction is endothermic, that is, accomplished with the absorp- 

 tion and not the liberation of energy. The conditions of this 

 synthesis are, first, a sufficient concentration of carbon dioxide 

 and water vapour ; second, an adequate energy supply for the 

 dissociation of the carbon dioxide and water molecules. It 

 has also been shown by Horstman Fenton 2 that a similar 

 synthesis of formaldehyde may be obtained from an aqueous 

 solution of carbon dioxide and water, in the presence of 

 magnesium — this reaction being enhanced by the presence of 

 weak bases. It is to be noted that the synthesis of form- 

 aldehyde or its polymeres in the plant is accomplished in the 

 presence of magnesium (chlorophyll) under the action of light, 

 and it is known, from a long series of researches, that the 

 synthetic action of light and the silent electric discharge are 

 practically identical. 



Driven to a choice between these two possibilities, we may 

 note that a sufficient concentration of carbon dioxide or of 

 magnesium in the primeval ocean seems, so far as we may 



1 Loc. cit. 



2 Chem. Soc. London, 91, 6S7, 1907 ; Chem. News, 1907. 



38 



