﻿Ludimar 
  Hermann. 
  

  

  xxxix 
  

  

  whole 
  surface, 
  and 
  that 
  a 
  difference 
  of 
  potential 
  only 
  arises 
  when 
  the 
  cells 
  

   under 
  one 
  of 
  the 
  electrodes 
  are 
  injured. 
  This 
  was 
  a 
  fundamental 
  discovery 
  

   and, 
  although 
  at 
  that 
  time 
  the 
  source 
  of 
  electromotive 
  force 
  in 
  changes 
  of 
  

   distribution 
  of 
  ions 
  and 
  the 
  properties 
  of 
  semi-permeable 
  membranes 
  was 
  

   unknown, 
  the 
  facts 
  brought 
  to 
  light 
  by 
  Hermann 
  were 
  a 
  necessary 
  pre- 
  

   liminary 
  to 
  further 
  work 
  and 
  led 
  him 
  to 
  formulate 
  his 
  well-known 
  " 
  alteration- 
  

   theory." 
  According 
  to 
  this 
  theory, 
  any 
  spot 
  whose 
  chemical 
  nature 
  changes 
  

   in 
  the 
  direction 
  of 
  injury 
  or 
  death 
  becomes 
  electro-negative 
  in 
  the 
  sense 
  of 
  

   the 
  zinc 
  pole 
  of 
  the 
  Daniell 
  battery. 
  We 
  may 
  note 
  that 
  stress 
  is 
  here 
  laid 
  

   on 
  chemical 
  processes, 
  which 
  are 
  known 
  to 
  occur, 
  in 
  contradistinction 
  to 
  the 
  

   purely 
  hypothetical 
  view 
  of 
  Du 
  Bois 
  Beymond. 
  When 
  we 
  remember 
  that 
  

   this 
  work 
  was 
  done 
  in 
  the 
  laboratory 
  of 
  the 
  latter, 
  we 
  realise 
  that 
  some 
  

   courage 
  was 
  manifested 
  in 
  publishing 
  it. 
  

  

  A 
  further 
  step 
  was 
  taken 
  by 
  showing 
  that 
  any 
  part 
  of 
  a 
  muscle 
  in 
  a 
  state 
  of 
  

   activity 
  is 
  also 
  electro-negative 
  to 
  a 
  part 
  at 
  rest. 
  Thus, 
  there 
  is 
  a 
  similarity 
  

   in 
  the 
  nature 
  of 
  the 
  process 
  of 
  contraction 
  to 
  that 
  which 
  is 
  associated 
  with 
  

   injury, 
  as 
  already 
  known 
  in 
  connection 
  with 
  the 
  production 
  of 
  acid 
  in 
  

   activity 
  and 
  in 
  rigor 
  mortis. 
  Accurate 
  and 
  delicate 
  apparatus 
  was 
  devised 
  in 
  

   order 
  to 
  follow 
  the 
  time 
  course 
  of 
  the 
  " 
  current 
  of 
  action," 
  which 
  was 
  found 
  

   to 
  progress 
  in 
  the 
  form 
  of 
  a 
  wave 
  from 
  the 
  point 
  stimulated. 
  If 
  the 
  

   electrodes 
  were 
  situated 
  at 
  unequal 
  distances 
  from 
  such 
  a 
  point, 
  that 
  one 
  

   nearest 
  to 
  it 
  became 
  negative 
  first, 
  the 
  further 
  point 
  following 
  with 
  a 
  similar 
  

   change. 
  By 
  this 
  means, 
  the 
  galvanometer 
  showed 
  a 
  deflection 
  first 
  in 
  one 
  

   direction, 
  then 
  in 
  the 
  opposite 
  direction, 
  the 
  so-called 
  " 
  diphasic 
  variation." 
  

   Any 
  two 
  points 
  in 
  the 
  same 
  stage 
  of 
  activity 
  are 
  equipotential. 
  An 
  

   important 
  practical 
  application 
  of 
  these 
  facts 
  will 
  be 
  mentioned 
  later. 
  

  

  The 
  chemical 
  or 
  rather 
  physico-chemical 
  point 
  of 
  view 
  taken 
  in 
  the 
  pre- 
  

   ceding 
  researches 
  naturally 
  led 
  on 
  to 
  further 
  investigation 
  of 
  the 
  nature 
  of 
  

   muscular 
  contraction. 
  It 
  was 
  first 
  shown 
  that 
  muscle 
  is 
  capable 
  of 
  executing 
  

   a 
  prolonged 
  series 
  of 
  contractions 
  in 
  vacuo. 
  Hence 
  the 
  energy 
  is 
  not 
  derived 
  

   directly 
  from 
  an 
  oxidation 
  process, 
  but 
  from 
  some 
  store 
  of 
  potential 
  energy 
  

   present 
  in 
  the 
  resting 
  muscle. 
  Hermann 
  found 
  that 
  carbon 
  dioxide 
  was 
  

   given 
  off, 
  although 
  it 
  was 
  reserved 
  for 
  Fletcher 
  at 
  a 
  later 
  date 
  to 
  show 
  that 
  

   this 
  was 
  derived 
  from 
  a 
  secondary 
  reaction 
  not 
  involved 
  in 
  the 
  essential 
  

   process. 
  

  

  Hermann 
  called 
  the 
  hypothetical 
  substance 
  from 
  which 
  the 
  contractile 
  

   energy 
  was 
  obtained, 
  inogen, 
  and 
  in 
  the 
  belief 
  that 
  carbon 
  dioxide 
  was 
  evolved 
  

   in 
  its 
  decomposition, 
  inogen 
  was 
  interpreted 
  as 
  a 
  compound 
  of 
  a 
  protein 
  

   constituent 
  of 
  muscle 
  (" 
  myosin 
  "), 
  carbon 
  dioxide, 
  and 
  lactic 
  acid, 
  which 
  

   latter 
  was 
  also 
  known 
  to 
  be 
  produced. 
  He 
  held 
  that 
  these 
  two 
  latter 
  

   substances 
  were 
  given 
  off 
  into 
  the 
  blood, 
  while 
  the 
  nitrogenous 
  constituent 
  

   was 
  used 
  again 
  to 
  reproduce 
  the 
  original 
  compound 
  by 
  the 
  assistance 
  of 
  

   energy 
  derived 
  from 
  food 
  arriving 
  in 
  the 
  blood. 
  Although 
  we 
  know 
  now 
  

   that 
  the 
  only 
  essential 
  part 
  of 
  the 
  contractile 
  process 
  is 
  the 
  separation 
  of 
  

   lactic 
  acid, 
  and 
  on 
  the 
  surface 
  of 
  certain 
  structural 
  constituents 
  of 
  the 
  muscle 
  

  

  VOL. 
  XCI. 
  — 
  B. 
  / 
  

  

  