﻿PHOTOSYNTHESIS 
  AND 
  THE 
  POSSIBLE 
  USE 
  OF 
  SOLAK 
  

  

  ENEKGY. 
  1 
  

  

  By 
  H. 
  A. 
  Spoehr, 
  

   Carnegie 
  Institution 
  of 
  Washington, 
  Coastal 
  Laboratory, 
  Carmel, 
  Calif. 
  

  

  The 
  purpose 
  of 
  the 
  following 
  brief 
  outline 
  is 
  to 
  show 
  that 
  while 
  the 
  photo- 
  

   synthetic 
  process 
  of 
  the 
  plant 
  is 
  at 
  present 
  the 
  only 
  means 
  we 
  have 
  of 
  utiliz- 
  

   ing 
  solar 
  energy, 
  this 
  method 
  is 
  so 
  very 
  inefficient 
  and 
  subject 
  to 
  such 
  great 
  

   uncertainties 
  that 
  it 
  is 
  exceedingly 
  doubtful 
  whether 
  it 
  can 
  be 
  depended 
  upon 
  

   to 
  maintain 
  our 
  energy 
  requirements. 
  In 
  other 
  words, 
  our 
  civilization 
  is 
  using 
  

   energy 
  at 
  a 
  prodigious 
  rate, 
  and 
  we 
  would 
  be 
  depending 
  upon 
  the 
  exceedingly 
  

   inefficient 
  and 
  slow 
  process 
  of 
  photosynthesis 
  to 
  supplant 
  the 
  supplies 
  which 
  

   have 
  been 
  stored 
  for 
  centuries 
  and 
  are 
  now 
  being 
  depleted. 
  Add 
  to 
  this, 
  that 
  

   in 
  order 
  to 
  supply 
  food 
  for 
  our 
  increasing 
  population 
  no 
  encroachment 
  on 
  

   agricultural 
  industry 
  would 
  be 
  permissible. 
  Theoretical 
  speculations 
  of 
  the 
  

   nature 
  of 
  what 
  might 
  be 
  accomplished 
  if, 
  for 
  instance, 
  all 
  the 
  arable 
  land 
  were 
  

   cultivated, 
  are 
  of 
  no 
  consequence 
  to 
  the 
  problem. 
  Conditions, 
  economic 
  and 
  

   social, 
  must 
  be 
  faced 
  as 
  they 
  exist. 
  The 
  inertia 
  of 
  our 
  civilization 
  is 
  such 
  

   that 
  great 
  changes 
  are 
  induced 
  only 
  by 
  the 
  labored 
  movements 
  of 
  evolution 
  

   or 
  by 
  catastrophe. 
  What 
  part, 
  then, 
  can 
  science 
  and 
  engineering 
  play 
  in 
  the 
  

   solution 
  of 
  this 
  problem? 
  

  

  First 
  of 
  all, 
  it 
  is 
  the 
  function 
  of 
  scientists 
  to 
  exercise 
  foresight 
  in 
  matters 
  

   regarding 
  the 
  material 
  welfare 
  of 
  humanity. 
  The 
  experiences 
  of 
  the 
  various 
  

   scientific 
  bodies 
  called 
  together 
  to 
  cope 
  with 
  the 
  many 
  problems 
  incident 
  to 
  the 
  

   war, 
  concur 
  in 
  the 
  conclusion 
  that 
  very 
  rarely 
  is 
  necessity 
  the 
  parent 
  of 
  inven- 
  

   tion 
  where 
  difficult 
  and 
  highly 
  complex 
  problems 
  are 
  concerned. 
  So 
  for 
  this 
  

   work 
  there 
  will 
  be 
  required 
  an 
  enormous 
  amount 
  of 
  patient 
  labor, 
  which 
  natu- 
  

   rally 
  should 
  be 
  begun 
  long 
  before 
  the 
  situation 
  becomes 
  acute. 
  

  

  It 
  has 
  frequently 
  been 
  said 
  of 
  our 
  earth 
  that 
  there 
  are 
  no 
  exports 
  

   and 
  no 
  imports 
  aside 
  from 
  occasional 
  meteorites. 
  This 
  is 
  true 
  as 
  far 
  

   as 
  matter 
  is 
  concerned, 
  but 
  it 
  is 
  not 
  true 
  when 
  energy 
  is 
  considered. 
  

   Matter 
  and 
  energy 
  are 
  the 
  two 
  fundamental 
  entities 
  in 
  our 
  concep- 
  

   tions 
  of 
  all 
  physical 
  phenomena. 
  As 
  scientific 
  thought 
  progresses, 
  

   ever-increasing 
  attention 
  is 
  being 
  given 
  to 
  the 
  paramount 
  impor- 
  

   tance 
  of 
  energy 
  relations 
  in 
  the 
  interpretation 
  of 
  natural 
  phenomena. 
  

   Matter 
  is 
  of 
  interest 
  to 
  us 
  largely 
  in 
  so 
  far 
  as 
  it 
  exhibits 
  certain 
  

   properties 
  and 
  undergoes 
  definite 
  changes. 
  In 
  viewing 
  the 
  common 
  

   materials 
  upon 
  which 
  we 
  depend 
  for 
  the 
  maintenance 
  and 
  propaga- 
  

   tion 
  of 
  life, 
  it 
  is 
  evident 
  that 
  we 
  are 
  less 
  interested 
  in 
  the 
  matter 
  

   as 
  such 
  than 
  its 
  ability 
  to 
  undergo 
  certain 
  changes 
  which 
  contribute 
  

  

  1 
  Reprinted 
  by 
  permission 
  from 
  the 
  Journal 
  of 
  Industrial 
  and 
  Engineering 
  Chemistry, 
  

   vol. 
  14, 
  no. 
  12, 
  December, 
  1922. 
  

  

  176 
  

  

  