SOURCES OF ENERGY 



l6l 



unnecessary difficulties sucli as tfie need to discover tfie con- 

 ditions under which a completely oxidised compound (cOo) 

 could be converted into organic compounds of high energy. 

 These investigators devoted the greater part of their attention 

 to resolving these problems although what they should, in 

 fact, have explained first was how carbon dioxide itself could 

 arise under the conditions present on the primaeval Earth. 



BIOSPHERE 



LIVING MATTER 



SEDIMENTARY 

 LAYERS 



CARBONATES 



I 



CARBONATES 



CARBONATES 



PETROLEUM S\ 



JUVENILE CH 

 LAYERS 



\' 



METALLIC 

 CARBIDES 



COALS 



\ 



NATIVE CARBON 

 GRAPHITES 



/ 



LIVING 

 MATTER 



CARBONATES 



c 



CO, 



CARBONATES 



NATIVE GRAPHITES 



CALCIUM 

 'alum IN 

 SILICATES 



CARBONO 

 SILICATES 



CARBONATES 



CO2 



CARBIDES 



QO^-METALLIC CARBONATES 



DIAMONDS^ 



Fig. 12. The circulation of carbon (after Vernadskii). 



Sources of energy. 



Nevertheless these investigations are of great interest to 

 us in spite of the false assumptions on which they were based 

 because they revealed the sources of energy which could be 

 used on the primitive Earth, if not for the reduction of 

 carbon dioxide, then for the oxidation and transformation of 

 the primaeval hydrocarbons. 



Solar radiation would seem to have been the greatest source 

 of energy on the surface of the Earth. The over-all amount 

 of energy of the solar radiation reaching the outer limits of 

 the atmosphere is 1-2 x 10'' kcal/year-^*' About 55 per cent 

 of this energy is absorbed by the atmosphere and giound 

 and, after a number of transformations, it leaves the Earth 



11 



