﻿OF 
  THE 
  DOCTRINE 
  OF 
  VITAL 
  AFFINITY. 
  397 
  

  

  mencing 
  the 
  subject 
  of 
  Digestion 
  in 
  his 
  anatomical 
  lectures. 
  " 
  Some 
  tell 
  you 
  that 
  

   we 
  have 
  here 
  a 
  fermenting 
  vat, 
  and 
  some 
  tell 
  you 
  we 
  have 
  a 
  stewpan, 
  but 
  I 
  tell 
  

   you 
  we 
  have 
  a 
  stomach." 
  And 
  when 
  we 
  remember 
  how 
  little 
  has 
  been 
  done 
  to 
  

   elucidate 
  the 
  function 
  of 
  digestion 
  by 
  likening 
  the 
  changes 
  in 
  the 
  stomach 
  either 
  

   to 
  fermentation 
  or 
  to 
  chemical 
  solution 
  (although 
  both 
  are 
  principles 
  which 
  

   appear 
  to 
  act 
  to 
  a 
  certain 
  extent), 
  and 
  how 
  much 
  comparative 
  anatomists 
  and 
  

   physiologists 
  have 
  done, 
  by 
  extending 
  their 
  inquiries 
  into 
  other 
  classes 
  of 
  ani- 
  

   mals, 
  and 
  studying 
  in 
  all, 
  the 
  changes 
  which 
  commence 
  in 
  the 
  stomach 
  and 
  ter- 
  

   minate 
  in 
  the 
  different 
  organs 
  of 
  excretion— 
  to 
  establish 
  laws 
  peculiar 
  to 
  physio- 
  

   logy, 
  under 
  which 
  so 
  many 
  forms 
  of 
  structure, 
  and 
  so 
  many 
  vital 
  operations 
  may 
  

   be 
  arranged, 
  — 
  we 
  can 
  hardly 
  fail 
  to 
  admit 
  that 
  this 
  distinction 
  was 
  wisely 
  drawn. 
  

   Indeed, 
  the 
  whole 
  science 
  of 
  Morphology, 
  or 
  of 
  the 
  analogies 
  of 
  the 
  structures 
  

   formed 
  by 
  living 
  action— 
  as 
  it 
  is 
  certainly 
  a 
  branch 
  of 
  knowledge 
  strictly 
  sui 
  

   generis 
  — 
  may 
  be 
  said 
  to 
  furnish 
  an 
  illustration 
  of 
  the 
  advantage 
  of 
  keeping 
  the 
  

   investigation 
  of 
  the 
  laws 
  of 
  living 
  action 
  entirely 
  separate 
  from 
  all 
  other 
  scientific 
  

   inquiries. 
  

  

  But 
  the 
  authority 
  to 
  which 
  I 
  would 
  wish 
  particularly 
  to 
  refer, 
  as 
  sanctioning 
  

   and 
  authorising 
  the 
  view 
  of 
  the 
  chemical 
  phenomena 
  of 
  the 
  living 
  body 
  which 
  I 
  

   here 
  advocate, 
  is 
  that 
  of 
  Haller, 
  whose 
  great 
  achievement 
  in 
  physiology 
  was 
  

   simply 
  that 
  of 
  establishing 
  the 
  strictly 
  vital 
  nature, 
  and 
  laying 
  down 
  the 
  most 
  

   important 
  laws, 
  of 
  the 
  living 
  property 
  of 
  Contractility 
  ; 
  the 
  only 
  property 
  con- 
  

   cerned 
  in 
  organic 
  life 
  which 
  is 
  expressly 
  admitted 
  by 
  Dr 
  Daubeny 
  to 
  be 
  truly 
  

   vital, 
  but 
  to 
  the 
  assertion 
  of 
  which 
  the 
  mechanical 
  physiologists 
  of 
  that 
  age 
  were 
  

   opposed, 
  on 
  grounds, 
  as 
  it 
  appears 
  to 
  me, 
  exactly 
  analogous 
  to 
  those 
  on 
  which 
  the 
  

   doctrine 
  of 
  vital 
  affinity 
  is 
  now 
  opposed, 
  because 
  it 
  had 
  not 
  been 
  proved 
  how 
  far 
  the 
  

   mechanical 
  properties 
  of 
  matter 
  were, 
  or 
  were 
  not, 
  adequate 
  to 
  explain 
  the 
  move- 
  

   ments 
  of 
  living 
  bodies. 
  

  

  " 
  As 
  all 
  physiology," 
  says 
  Haller, 
  " 
  involves 
  a 
  history 
  of 
  motions 
  by 
  which 
  

   the 
  animal 
  machine 
  is 
  agitated, 
  and 
  as 
  all 
  motions 
  have 
  their 
  own 
  laws, 
  we 
  can 
  

   perceive 
  why, 
  about 
  the 
  end 
  of 
  last 
  century, 
  the 
  principles 
  of 
  hydraulics, 
  hydro- 
  

   statics, 
  and 
  mechanics, 
  were 
  transferred 
  to 
  physiology. 
  There 
  is 
  a 
  difficulty 
  in 
  

   this 
  matter, 
  however, 
  and 
  if 
  we 
  reckon 
  up 
  all 
  the 
  good, 
  and 
  all 
  the 
  evil, 
  which 
  

   has 
  been 
  done 
  to 
  physiology, 
  by 
  the 
  cultivation 
  of 
  these 
  sciences, 
  some 
  may 
  think 
  

   that 
  we 
  might 
  gladly 
  renounce 
  all 
  the 
  good, 
  for 
  the 
  sake 
  of 
  escaping 
  the 
  evil. 
  

   There 
  are 
  certainly 
  many 
  things 
  in 
  the 
  animal 
  economy 
  very 
  different 
  from 
  the 
  

   effects 
  of 
  ordinary 
  mechanical 
  laws 
  ; 
  great 
  movements 
  excited 
  by 
  slight 
  causes 
  ; 
  

   the 
  flow 
  of 
  fluids 
  hardly 
  diminished 
  by 
  causes 
  which, 
  according 
  to 
  established 
  

   mechanical 
  laws, 
  ought 
  to 
  arrest 
  them 
  entirely 
  ; 
  motions 
  excited 
  by 
  unperceived 
  

   causes 
  ; 
  vigorous 
  movements 
  produced 
  by 
  the 
  contraction 
  of 
  weak 
  fibres, 
  &c. 
  ; 
  

   from 
  which 
  I 
  do 
  not 
  infer, 
  that 
  simply 
  physical 
  laws 
  are 
  to 
  be 
  repudiated 
  in 
  phy- 
  

   siology 
  ; 
  but 
  this 
  I 
  maintain, 
  that 
  they 
  are 
  never 
  to 
  be 
  transferred 
  to 
  tlie 
  ex-plana- 
  

  

  VOL. 
  xx. 
  PART 
  III. 
  5 
  p 
  

  

  