BEGINNINGS OF LIFE 27 



aluminum or magnesium, easily and rapidly formed in the 

 cooling substrate. Acted upon by the dense water vapor, 

 these nitrides produced ammonia (nitrogen and hydrogen) ; 

 or carbides reacting with nitrogen formed cyanamides 

 which combined with the hot steam to form ammonia as 

 one of the products. 



The formation of nitrides and ammonia and of carbides 

 and hydrocarbons is the first step in the evolution of the 

 living, a step that is being taken in the atmosphere of the 

 stars. With water vapor the hydrocarbons form alcohols, 

 aldehydes, ketones, and organic acids; and with ammonia 

 these substances give rise to amines and amides. All these 

 compounds are the raw materials of life, and they must have 

 literally rained into the swelling seas on our early earth. 



Our chemists of today can take these compounds and 

 synthesize them into innumerable complex organic sub- 

 stances; there is no reason to suppose that nature could not 

 have done as much, easily and quite without outside help. 

 In the organic synthesis which begins at this point, in the 

 laboratory or in nature, the carbon atoms are joined in 

 longer and longer chains (condensation) ; organic molecules 

 are held in union by an atom of oxygen or nitrogen (poly- 

 merization); and there is oxidation through the action of 

 the hydroxyl ion of water. Sugars, an energy source of the 

 organism, slowly formed in the sunlight, even in nature, 

 from formaldehyde (carbon, hydrogen, oxygen) long be- 

 fore the evolution of chlorophyll. Fats— also made up of 

 carbon, hydrogen, oxygen, and a great energy storehouse 

 for the organism— were easily synthesized from long-chain 

 hydrocarbon acids and glycerol. Glycol (the double al- 

 cohol), finally forming, split its groups: one to be oxidized 

 to form an acid, the other to react with ammonia to form 

 an amine; and the amino acids appeared. 



With the advent of the amino acids (carbon, hydrogen, 

 oxygen, nitrogen) the real building blocks of proteins and 

 hence eventually of protoplasm are present and the next-to- 



