﻿THE 
  MYSTERY 
  OF 
  LIFE 
  

  

  By 
  F. 
  G. 
  DoNNAN, 
  F. 
  R. 
  S. 
  

  

  During 
  the 
  last 
  40 
  years 
  the 
  sciences 
  of 
  physics 
  and 
  chemistry 
  

   have 
  made 
  tremendous 
  strides. 
  The 
  physicochemical 
  world 
  has 
  

   been 
  analyzed 
  into 
  three 
  components 
  — 
  electrons, 
  protons, 
  and 
  the 
  

   electromagnetic 
  field 
  with 
  its 
  streams 
  of 
  radiant 
  energy. 
  Concur- 
  

   rently 
  with 
  these 
  advances 
  astronomy 
  has 
  progressed 
  to 
  an 
  extent 
  

   undreamed 
  of 
  40 
  years 
  ago. 
  The 
  distances, 
  sizes, 
  masses, 
  tempera- 
  

   tures, 
  and 
  even 
  the 
  constitutions 
  of 
  far-distant 
  stars 
  have 
  been 
  ascer- 
  

   tained 
  and 
  compared. 
  The 
  evolution 
  of 
  the 
  almost 
  inconceivably 
  

   distant 
  nebulse 
  and 
  their 
  condensation 
  into 
  stars 
  and 
  star 
  clusters 
  

   have 
  been 
  unraveled 
  with 
  a 
  skill 
  and 
  knowledge 
  that 
  would 
  have 
  

   been 
  deemed 
  superhuman 
  a 
  hundred 
  years 
  ago. 
  Amidst 
  the 
  vast 
  

   cosmos 
  thus 
  disclosed 
  to 
  the 
  mind 
  of 
  man, 
  our 
  sun 
  winds 
  its 
  modest 
  

   way, 
  an 
  unimportant 
  star, 
  old 
  in 
  years 
  and 
  approaching 
  death. 
  

   Once 
  upon 
  a 
  time, 
  so 
  the 
  astronomers 
  tell 
  us, 
  its 
  surface 
  was 
  rippled 
  

   by 
  the 
  gravitational 
  pull 
  of 
  a 
  passing 
  star, 
  and 
  the 
  ripples 
  becoming 
  

   waves, 
  broke 
  and 
  splashed 
  off. 
  Some 
  drops 
  of 
  this 
  glowing 
  spray, 
  

   held 
  by 
  ihe 
  sun's 
  attraction 
  in 
  revolving 
  orbits, 
  cooled 
  down 
  and 
  

   became 
  the 
  planets 
  of 
  our 
  solar 
  system. 
  Our 
  own 
  planet, 
  the 
  earth, 
  

   gradually 
  acquired 
  a 
  solid 
  crust. 
  Then 
  the 
  water 
  vapor 
  in 
  its 
  atmos- 
  

   phere 
  began 
  to 
  condense, 
  and 
  produced 
  oceans, 
  lakes 
  and 
  rivers 
  as 
  

   the 
  temperature 
  sank. 
  It 
  is 
  probably 
  at 
  least 
  a 
  thousand 
  million 
  

   5^ears 
  since 
  the 
  earth 
  acquired 
  a 
  solid 
  crust 
  of 
  rock. 
  During 
  that 
  

   period 
  living 
  beings, 
  plants 
  and 
  animals, 
  have 
  appeared, 
  and, 
  as 
  

   the 
  story 
  of 
  the 
  rocks 
  tells 
  us, 
  have 
  developed 
  by 
  degrees 
  from 
  small 
  

   and 
  lowly 
  ancestors. 
  The 
  last 
  product 
  of 
  this 
  development 
  is 
  the 
  mind 
  

   of 
  man. 
  What 
  a 
  strange 
  story! 
  On 
  the 
  cool 
  surface 
  of 
  this 
  little 
  

   planet, 
  warmed 
  by 
  the 
  rays 
  of 
  a 
  declining 
  star, 
  stands 
  the 
  small 
  

   company 
  of 
  life. 
  One 
  with 
  the 
  green 
  meadows 
  and 
  the 
  flowers, 
  the 
  

   birds 
  and 
  the 
  fishes 
  and 
  the 
  beasts, 
  man 
  with 
  all 
  his 
  kith 
  and 
  kin 
  

   counts 
  for 
  but 
  an 
  infinitesimal 
  fraction 
  of 
  the 
  surface 
  of 
  the 
  earth, 
  and 
  

   yet 
  it 
  is 
  the 
  mind 
  of 
  man 
  that 
  has 
  penetrated 
  the 
  cosmos 
  and 
  dis- 
  

   covered 
  the 
  distant 
  stars 
  and 
  nebulae. 
  Truly 
  we 
  may 
  say 
  that 
  life 
  

  

  1 
  Evening 
  discourse 
  before 
  the 
  British 
  Association 
  for 
  the 
  Advancement 
  of 
  Science 
  at 
  the 
  Glasgow 
  Meet- 
  

   ing, 
  1928. 
  Reprinted 
  by 
  permission 
  of 
  the 
  association. 
  

  

  309 
  

  

  