﻿OF 
  THE 
  DOCTRINE 
  OF 
  VITAL 
  AFFINITY. 
  389 
  

  

  matter 
  originally 
  introduced 
  from 
  vegetables 
  is 
  applied 
  to 
  the 
  nutritive 
  assimila- 
  

   tion 
  and 
  formation 
  of 
  the 
  living 
  textures, 
  other 
  portions 
  of 
  the 
  same 
  elements, 
  

   previously 
  used 
  in 
  the 
  same 
  process, 
  are 
  continually 
  yielding 
  to 
  the 
  influence, 
  

   previously 
  resisted, 
  of 
  the 
  oxygen 
  of 
  the 
  air, 
  and 
  are 
  forming 
  another 
  set 
  of 
  com- 
  

   pounds, 
  by 
  the 
  process 
  of 
  destructive 
  assimilation, 
  which 
  are 
  ready 
  to 
  take 
  the 
  

   form 
  of 
  crystals 
  ; 
  which 
  either 
  already 
  possess, 
  or 
  rapidly 
  tend 
  to, 
  the 
  composi- 
  

   tion 
  of 
  the 
  inorganic 
  matter 
  whence 
  all 
  these 
  compounds 
  originate 
  ; 
  — 
  which 
  are 
  

   poisonous 
  if 
  retained 
  in 
  the 
  body, 
  and 
  for 
  which, 
  therefore, 
  outlets 
  are 
  provided 
  

   in 
  the 
  organs 
  of 
  excretion, 
  so 
  as 
  to 
  justify 
  the 
  striking 
  expression 
  of 
  Cuviek, 
  that 
  

   all 
  living 
  animal 
  matter, 
  although 
  the 
  depository 
  of 
  force 
  which 
  will 
  compel 
  other 
  

   matter 
  to 
  follow 
  the 
  same 
  course 
  as 
  itself, 
  will 
  soon 
  occupy 
  its 
  own 
  place 
  no 
  

   longer. 
  This 
  is 
  a 
  series 
  of 
  chemical 
  changes 
  quite 
  distinct 
  from 
  anything 
  seen 
  in 
  

   any 
  other 
  circumstances 
  of 
  Nature. 
  And 
  farther, 
  we 
  know, 
  in 
  regard 
  to 
  the 
  power 
  

   exciting 
  these, 
  that 
  it 
  is 
  obedient 
  to 
  certain 
  laws 
  of 
  animal 
  life, 
  to 
  which 
  nothing 
  

   analogous 
  is 
  seen 
  in 
  other 
  chemical 
  operations 
  ; 
  nutrition 
  and 
  secretion 
  being 
  

   liable 
  to 
  sudden 
  and 
  important 
  change, 
  as 
  living 
  movements 
  are, 
  by 
  living 
  changes 
  

   in 
  nervous 
  matter, 
  e. 
  g., 
  by 
  those 
  which 
  attend 
  certain 
  acts 
  of 
  mind 
  ; 
  and 
  farther, 
  

   every 
  such 
  action 
  being 
  liable 
  to 
  diminution 
  or 
  exhaustion 
  by 
  the 
  degree 
  in 
  which 
  

   it 
  is 
  itself 
  exercised. 
  

  

  It 
  will 
  be 
  observed, 
  that 
  all 
  these 
  are 
  peculiarities 
  in 
  the 
  chemical 
  nature 
  and 
  

   constitution, 
  even 
  of 
  the 
  minutest 
  particles 
  of 
  all 
  living 
  structures; 
  and 
  that 
  

   without 
  reference 
  to 
  them 
  nothing 
  living 
  can 
  be 
  characterised. 
  These 
  phenomena 
  

   are 
  just 
  as 
  distinctly 
  peculiar 
  to 
  living 
  bodies, 
  and 
  characteristic 
  of 
  their 
  living- 
  

   state, 
  as 
  the 
  contraction 
  of 
  muscles, 
  whether 
  produced 
  by 
  irritations 
  of 
  their 
  own 
  

   fibres 
  or 
  of 
  the 
  nerves 
  entering 
  them 
  ; 
  and 
  they 
  are 
  muc'i 
  more 
  general 
  in 
  all 
  

   classes 
  of 
  living 
  beings. 
  If 
  anything 
  in 
  the 
  economy 
  of 
  living 
  beings 
  demands 
  

   explanation, 
  or 
  is 
  deserving 
  of 
  being 
  made 
  the 
  object 
  of 
  scientific 
  research, 
  it 
  must 
  

   be 
  these, 
  their 
  most 
  essential 
  characteristics. 
  If 
  they 
  are 
  not 
  of 
  such 
  importance 
  as 
  

   to 
  demand 
  special 
  investigation, 
  — 
  if 
  it 
  is 
  only 
  the 
  movements 
  of 
  the 
  particles 
  

   concerned 
  either 
  in 
  the 
  development 
  of 
  vegetables, 
  or 
  the 
  varied 
  functions 
  of 
  

   animals, 
  that 
  we 
  ought 
  to 
  regard 
  as 
  peculiar 
  to 
  living 
  bodies, 
  — 
  then 
  Physiology, 
  

   so 
  far 
  as 
  these 
  properties 
  of 
  living 
  bodies 
  are 
  concerned, 
  has 
  no 
  claim 
  to 
  the 
  title 
  

   of 
  a 
  separate 
  science, 
  it 
  is 
  only 
  a 
  branch 
  of 
  Chemistry. 
  But 
  it 
  is 
  just 
  as 
  probable, 
  

   a 
  priori, 
  that 
  the 
  laws 
  of 
  chemistry 
  should 
  undergo 
  a 
  modification 
  in 
  living 
  

   bodies, 
  as 
  that 
  the 
  laws 
  of 
  motion 
  should 
  be 
  made 
  subordinate 
  in 
  certain 
  parts 
  

   of 
  living 
  animals, 
  to 
  the 
  vital 
  property 
  of 
  Irritability 
  of 
  muscles, 
  as 
  explained 
  

   by 
  Haller 
  ; 
  and 
  the 
  very 
  peculiar 
  changes 
  which 
  are 
  observed 
  in 
  tracing 
  the 
  

   course 
  of 
  the 
  elements 
  of 
  water, 
  carbonic 
  acid, 
  and 
  ammonia, 
  which 
  are 
  absorbed 
  

   by 
  vegetables, 
  until 
  they 
  pass 
  out 
  in 
  the 
  form 
  of 
  water, 
  carbonic 
  acid, 
  and 
  am- 
  

   monia 
  (or 
  in 
  compounds 
  immediately 
  resolvable 
  into 
  them), 
  in 
  the 
  excretions 
  of 
  

  

  VOL. 
  XX. 
  PART 
  III. 
  5 
  N 
  

  

  