The formation of amino acids from purely inorganic 

 molecules — methane, ammonia, water, carbon dioxide — 

 has been accomplished by the passage of an electric dis- 

 charge through mixtures of these gases in the laboratory. 

 The conditions under which these experiments were per- 

 formed were chosen to approximate to those which prob- 

 ably existed in the terrestrial atmosphere in the early part 

 of the geological history of the Earth, when lightning dis- 

 charges would have taken place frequently in the turbulent 

 gases. Thus there appears today to be significant evidence 

 concerning the origination of life on Earth which suggests, 

 quite strongly, that it arose from non-living matter under 

 the influence of natural forces. The presence of viruses 

 on the present-day Earth — molecules, intermediate in 

 size and other properties between the chromosomes of 

 living organisms and non-living organic molecules — 

 adds confirmation to the inorganic hypothesis of the ori- 

 gin of life. 



Perhaps the discovery, as one of the major causes 

 of disease, of bacteria (microbes or germs) in the last 

 century, leading to the practical control of bacterial dis- 

 eases, has done as much to convince people of the effect- 

 iveness of scientific methods of solving problems as have 

 advances in any other field of scientific application. The 

 largest credit for showing that microscopic living organisms 

 were responsible for important human, and animal dis- 

 eases, must go to Pasteur (1858-) whose researches really 

 established bacteriology as an essential part of medicine. 



Pasteur was studying the chemical substances produced 

 during the process used in the fermentation of wine, and 

 he noted that under the microscope the fermenting liquid 

 was seen to contain numerous small cells without nuclei. 

 These cells, if transferred to a solution of sugars, caused 



56 



