142 SIMPLER ORGANIC SUBSTANCES 



Goldschmidt has shown that a considerable amount o£ metal- 

 lic nitrides must also form part of the iron-nickel core of the 

 Earth. The reaction between metallic nitrides and water 

 gives rise to ammonia according to the equation 



FeN -I- 3H20->Fe(OH)3 -f NHg 



Geological findings also point to the presence of ammonium 

 salts in the lithosphere. V. Vernadskir^^ wrote as follows : 



Chlorides and fluorides of ammonium are undoubtedly pro- 

 duced by volcanoes. These can only be partly attributed to the 

 destruction of nitrogenous residues of living material carried 

 away by the lava. Life can in no way be associated with the 

 production of ammonia together with superheated steam (up 

 to 190° C) in the neighbourhood of geysers which arise from 

 depths of no less than 200 metres, such as those in Tuscany in 

 Italy and Sonoma in California. These gases, of magmatic origin, 

 are formed simultaneously with the steam. 



Ammoniacal aluminosilicates similar to kaolin apparently 

 exist as isomorphous mixtures of minerals in volcanic and deep 

 igneous formations, and the derivation of the primaeval nitrogen 

 from these sources seems very likely. 



By analogy with the carbides and nitrides, sulphides of 

 metals would seem to be the source from which the hydrogen 

 sulphide of the primaeval atmosphere was formed. 



The highly reduced atmosphere which has been described 

 could not remain unchanged on the Earth for ever. Only if 

 a planet is very large or the temperature is very low can 

 it hold all its hydrogen (as happens, for example, on Jupiter 

 and Saturn). The Earth does not seem to be large enough 

 for this so, as we have already pointed out, the hydrogen 

 of its atmosphere was always escaping. However, the ultra- 

 violet radiation of the Sun was constantly decomposing water 

 phorochemically in the upper layers of the atmosphere. The 

 hydrogen arising from these reactions escaped but the oxygen 

 oxidised ammonia to molecular nitrogen and converted the 

 primitive Hydrocarbons into various oxygen-containing or- 

 ganic compounds such as alcohols, aldehydes, ketones and 

 acids ; carbon monoxide and carbon dioxide appeared as 

 the final products of this oxidation, and it was from these 



