﻿THE 
  LINGERING 
  DRYAD 
  HEYL 
  207 
  

  

  It 
  often 
  happens 
  that 
  when 
  the 
  unknown 
  is 
  named 
  it 
  appears 
  as 
  if 
  it 
  

   were 
  more 
  than 
  half 
  explained. 
  The 
  vital 
  force 
  once 
  named 
  soon 
  came 
  

   to 
  be 
  a 
  familiar 
  concept. 
  It 
  was 
  held 
  to 
  be 
  resident 
  in 
  living 
  matter, 
  

   whether 
  animal 
  or 
  vegetable, 
  much 
  like 
  the 
  dryad 
  in 
  the 
  tree. 
  It 
  was 
  

   believed 
  to 
  differ 
  in 
  kind 
  from 
  the 
  chemical 
  and 
  physical 
  forces 
  that 
  

   governed 
  the 
  formation 
  of 
  inorganic 
  compounds. 
  Under 
  the 
  influence 
  

   of 
  this 
  vital 
  force 
  it 
  was 
  believed 
  that 
  all 
  the 
  chemical 
  reactions 
  of 
  

   living 
  matter 
  took 
  place, 
  and 
  it 
  was 
  even 
  supposed 
  to 
  govern 
  the 
  

   decompositions 
  that 
  occurred 
  after 
  death. 
  

  

  The 
  belief 
  in 
  a 
  vital 
  force 
  of 
  this 
  nature 
  was 
  universal 
  among 
  eigh- 
  

   teenth 
  century 
  chemists, 
  even 
  Berzelius 
  being 
  found 
  among 
  its 
  adher- 
  

   ents. 
  The 
  vital 
  force 
  seems 
  to 
  have 
  been 
  regarded 
  with 
  something 
  like 
  

   the 
  awe 
  inspired 
  by 
  the 
  supernatural, 
  and 
  it 
  was 
  well 
  into 
  the 
  nine- 
  

   teenth 
  century 
  before 
  its 
  hold 
  on 
  men's 
  minds 
  began 
  to 
  relax. 
  

  

  The 
  past 
  year, 
  1928, 
  marked 
  the 
  century 
  of 
  an 
  epoch 
  in 
  human 
  

   thought, 
  for 
  it 
  was 
  just 
  100 
  years 
  since 
  the 
  doctrine 
  of 
  a 
  vital 
  force 
  

   received 
  its 
  logical 
  death 
  blow. 
  In 
  1828 
  Wohler 
  succeeded 
  in 
  produc- 
  

   ing 
  by 
  laboratory 
  methods 
  the 
  first 
  organic 
  compound. 
  This 
  was 
  urea, 
  

   which 
  he 
  prepared 
  by 
  simply 
  heating 
  an 
  inorganic 
  compound, 
  ammo- 
  

   nium 
  cyanate, 
  containing 
  the 
  same 
  elements 
  as 
  urea, 
  namely 
  carbon, 
  

   hydrogen, 
  oxygen, 
  and 
  nitrogen, 
  and 
  in 
  the 
  same 
  proportions. 
  

  

  This 
  was 
  a 
  body 
  blow 
  at 
  the 
  dryad, 
  but 
  she 
  died 
  hard. 
  Her 
  devoted 
  

   adherents 
  ralUed 
  to 
  her 
  support 
  and 
  explained 
  away 
  Wohler's 
  result 
  in 
  

   various 
  fashions. 
  In 
  this 
  they 
  were 
  aided 
  by 
  the 
  fact 
  that 
  for 
  years 
  

   this 
  synthesis 
  stood 
  alone, 
  suggesting 
  that 
  there 
  was 
  something 
  excep- 
  

   tional 
  about 
  it. 
  Some 
  said 
  that 
  this 
  proved 
  merely 
  that 
  a 
  mistake 
  had 
  

   been 
  made; 
  that 
  urea 
  was 
  not 
  really 
  an 
  organic 
  substance, 
  but 
  occupied 
  

   a 
  place 
  halfway 
  between 
  the 
  organic 
  and 
  inorganic 
  kingdoms. 
  Others 
  

   argued 
  curiously 
  that 
  the 
  carbon 
  of 
  the 
  cyanate 
  retained 
  some 
  trace 
  or 
  

   memory 
  of 
  the 
  vital 
  force 
  which 
  had 
  ruled 
  it 
  when 
  it 
  had 
  previously 
  

   been 
  a 
  part 
  of 
  some 
  organic 
  compound. 
  But 
  in 
  time 
  other 
  syntheses 
  

   were 
  achieved 
  in 
  such 
  numbers 
  that 
  the 
  accumulated 
  evidence 
  became 
  

   overwhelming, 
  and 
  it 
  was 
  finally 
  recognized 
  that 
  organic 
  chemistry 
  

   was 
  only 
  complicated 
  inorganic 
  chemistry, 
  and 
  that 
  the 
  difference 
  

   between 
  the 
  two 
  was 
  one 
  not 
  of 
  kind, 
  but 
  of 
  degree 
  of 
  complexity. 
  

  

  We 
  have 
  said 
  that 
  the 
  dryad 
  died 
  hard. 
  As 
  a 
  matter 
  of 
  fact 
  she 
  did 
  

   not 
  die 
  at 
  all 
  — 
  she 
  emigrated. 
  Dispossessed 
  by 
  the 
  advancing 
  frontier 
  

   of 
  knowledge 
  from 
  the 
  domain 
  of 
  organic 
  chemistry 
  which 
  had 
  so 
  long 
  

   afforded 
  her 
  a 
  refuge, 
  she 
  retreated 
  under 
  fire 
  into 
  a 
  less 
  understood 
  

   region 
  beyond 
  — 
  into 
  the 
  biological 
  sciences. 
  Here 
  the 
  complexity 
  of 
  

   phenomena 
  was 
  (and 
  still 
  is) 
  so 
  great 
  that 
  among 
  the 
  shadows 
  the 
  

   dryad 
  stiU 
  finds 
  a 
  retreat. 
  

  

  Biologists 
  of 
  to-day 
  are 
  divided 
  into 
  two 
  camps 
  — 
  vitalists 
  and 
  

   mechanists. 
  Between 
  them 
  a 
  conflict 
  rages, 
  and 
  the 
  fate 
  of 
  the 
  dryad 
  

   still 
  hangs 
  in 
  the 
  balance. 
  The 
  vitalists 
  argue 
  that 
  whatever 
  may 
  

  

  