110 SESSION I. DISCUSSION 



In the process of cooling of the planet the molten magma began to crystallize. The 

 transition from the liquid to xhe solid state was associated with a lowering of solubility 

 as a result of which a large quantity of gases was emitted and rushed outwards. 



At the same time there were taking place, within the solidifying magma, reactions 

 between hydrogen, carbon and oxygen and also between oxygen and some of the other 

 elements of the magma. Free oxygen is, as a rule, absent from the gases contained in 

 magmatic formations. During the slow cooling of the molten magma, part of the oxygen 

 of the water which had originally been dissolved in the magma, was used in the oxidation 

 of the elements of the magma. Among these were, in the first place, iron, which passed 

 from a lower to a higher state of oxidation, and calcium, which arose from the natural 

 radioactive decay of potassiimi. As a result, part of the oxygen of the water remained for 

 ever within the magma, while hydrogen, the inert gases, methane, carbon dioxide and 

 carbon monoxide passed outwards into the atmosphere. 



As the temperature fell, the differences in rate of permeation between the light and 

 heavy gases increased markedly. Thus, as concerned permeability by diffusion, under 

 the conditions which prevailed during the cooling of the crust of the Earth, the migration 

 of hydrogen from the interior to the surface was on an exceptionally large scale, out of 

 all proportion, from a quantitative point of view, to the relatively small-scale translocation 

 by diffusion of the other elements and compounds. 



Similar ideas about the flow of hydrogen out from the deeper parts of the Earth were 

 put forward by L. V. Khmelevskaya as early as 1947. 



To get an idea of the amount of hydrogen which could have reached the atmosphere 

 from the interior of the Earth, we may consider the crust of the Earth as being like a 

 membrane in air-free interplanetary space, which can only lose the gas dissolved in it 

 through one surface into the vacuum. Owing to our lack of factual data, we have to use 

 an arbitrary, probable figure for the original concentration. If we take it as being i vol. 

 of hydrogen (at NTP) per 10 vol. of formation, then, with a coefficient of diffusion of 

 I X 10"^ cm-/sec, it is easy to calculate the mass of hydrogen which will be given off" 

 into the atmosphere from a layer of the crust of the Earth 50 km thick in relation to 

 time. 



Such an approximate, indicative calculation shows that after 1000 million years from 

 the time when the process began lo*^ to 10'* tons of hydrogen could have entered the 

 atmosphere. However, the hydrogen and carbon dioxide entering the atmosphere from 

 the depths of the Earth were not the sole sources of the starting products for the primaeval 

 synthesis of organic substances. The beginning of crystallization of the magma was 

 accompanied by the differentiation of its components. The denser components of the 

 molten magma sank, while the less dense, acidic components rose towards the surface. 

 In the course of this, masses of elementary carbon were thrown out on to the surface 

 along with the lighter acidic components of the magma. The appearance of elementary 

 carbon on the surface of the Earth and its contact with the heated water vapour of the 

 atmosphere must have led to the formation of water gas. Unfortunately, we have no way 

 of gauging the scale on which this process occurred, but it is important to note that such 

 a process did occur, making possible the accumulation in the atmosphere of the starting 

 materials for the primary syntheses. 



In all probability it was just these two processes: the giving off of hydrogen from the 

 depths of the Earth and the formation of carbon dioxide on its surface, which accounted 

 for the accumulation in the atmosphere of the starting products for the primary synthesis 

 of organic substances and which prevented free oxygen from existing in the atmosphere. 

 Under these conditions it was possible for hydrocarbons, a certain amount of oxygen- 

 containing compounds as well as ammonia and hydrogen sulphide, to be formed and to 

 remain as such in the atmosphere. 



The primary synthesis must have occurred, for the most part, in the atmosphere in 

 contact with the surface of the crust of the Earth which contained substances with catalytic 

 properties. 



A relatively small quantity of organic substances, mostly methane, may have been 

 formed within the solidifying magma. But, as the crust of the Earth cooled, so its per- 

 meability decreased substantially and the accession to the atmosphere of organic sub- 

 stances from witliin it almost ceased. 



As the planet cooled further, water settled down on its surface and, later, also the 

 products of primary synthesis, which were distributed in the waters of the oceans where 

 further transformations occurred. One result of these was the formation of proteins. 



