﻿324 
  Dr. 
  M. 
  Foster 
  and 
  Mr. 
  A. 
  G. 
  Dew-Smith 
  on 
  the 
  [Mar. 
  18, 
  

  

  always 
  used. 
  The 
  current 
  was 
  supplied 
  by 
  a 
  single 
  Daniell's 
  or 
  Grenet's 
  

   cell, 
  the 
  circuit 
  being 
  divided 
  between 
  the 
  electrodes 
  placed 
  on 
  the 
  heart 
  

   and 
  a 
  set 
  of 
  resistance-coils, 
  the 
  resistance 
  in 
  which 
  could 
  be 
  made 
  to 
  

   vary 
  from 
  *05 
  ohm 
  to 
  100,000 
  ohms, 
  and 
  thus 
  a 
  very 
  great 
  variety 
  

   obtained 
  in 
  the 
  strength 
  of 
  the 
  current 
  passing 
  through 
  the 
  heart. 
  

  

  It 
  will 
  be 
  as 
  well 
  to 
  begin 
  by 
  describing 
  the 
  effects 
  produced 
  by 
  the 
  

   constant 
  current 
  on 
  the 
  heart 
  at 
  rest, 
  i. 
  e. 
  on 
  hearts 
  which, 
  after 
  removal 
  

   from 
  the 
  body, 
  did 
  not 
  exhibit 
  any 
  spontaneous 
  beat. 
  

  

  When 
  the 
  ventricle 
  alone 
  was 
  experimented 
  with 
  (the 
  auricle 
  having 
  

   been 
  removed), 
  and 
  the 
  electrodes 
  placed 
  lengthwise, 
  one 
  against 
  the 
  

   auricular 
  end, 
  the 
  other 
  against 
  the 
  aortic 
  end 
  of 
  the 
  ventricle, 
  a 
  contrac- 
  

   tion 
  or 
  beat 
  always 
  took 
  place 
  at 
  the 
  making 
  and 
  at 
  the 
  breaking 
  of 
  the 
  

   circuit 
  ; 
  but 
  the 
  two 
  contractions 
  differed 
  from 
  each 
  other 
  and 
  from 
  a 
  

   normal 
  beat 
  in 
  a 
  very 
  distinct 
  manner. 
  

  

  The 
  normal 
  beat 
  of 
  the 
  ventricle 
  may 
  be 
  described 
  as 
  a 
  gathering 
  of 
  

   the 
  whole 
  mass 
  towards 
  the 
  point 
  where 
  the 
  long 
  axis 
  of 
  the 
  ventricle 
  

   would 
  be 
  intersected 
  by 
  a 
  transverse 
  line 
  drawn 
  across 
  the 
  ventricle's 
  

   broadest 
  part, 
  accompanied 
  by 
  a 
  kind 
  of 
  peristaltic 
  constriction, 
  which 
  

   travels 
  down 
  from 
  the 
  auricular 
  to 
  the 
  aortic 
  end, 
  i. 
  e. 
  which 
  begins 
  at 
  

   the 
  auricular 
  and 
  leaves 
  off 
  at 
  the 
  aortic 
  end, 
  though 
  during 
  the 
  greater 
  

   part 
  of 
  the 
  period 
  of 
  the 
  beat 
  the 
  whole 
  of 
  the 
  ventricle 
  is 
  constricted. 
  

   These 
  features 
  of 
  the 
  beat 
  may 
  be 
  recognized 
  in 
  an 
  ordinary 
  beat, 
  and 
  

   become 
  very 
  obvious 
  when 
  the 
  beat 
  is 
  abnormally 
  prolonged, 
  as 
  when 
  

   under 
  the 
  influence 
  of 
  certain 
  drugs 
  (atropine 
  &c). 
  From 
  this 
  normal 
  

   beat 
  the 
  beats 
  or 
  contractions 
  caused 
  by 
  the 
  closing 
  or 
  opening 
  of 
  a 
  con- 
  

   stant 
  current 
  differ 
  in 
  the 
  following 
  way. 
  

  

  The 
  closing- 
  or 
  making-beat 
  always 
  starts 
  from 
  the 
  kathode, 
  and 
  travels 
  

   for 
  a 
  variable 
  distance 
  towards 
  the 
  anode 
  ; 
  the 
  opening- 
  or 
  breaking-beat 
  

   always 
  starts 
  from 
  the 
  anode, 
  and 
  travels 
  towards 
  the 
  kathode, 
  the 
  beat 
  

   in 
  each 
  being 
  a 
  kind 
  of 
  peristaltic 
  contraction, 
  the 
  features 
  of 
  which 
  are 
  

   more 
  readily 
  recognized 
  when 
  it 
  starts 
  from 
  the 
  aortic 
  end. 
  

  

  This 
  kathodic 
  making-beat 
  and 
  anodic 
  breaking-beat 
  make 
  their 
  ap- 
  

   pearance 
  with 
  all 
  intensities 
  of 
  current 
  up 
  to 
  the 
  full 
  strength 
  of 
  a 
  

   Daniell's 
  cell 
  (beyond 
  this 
  we 
  have 
  never 
  gone), 
  whatever 
  be 
  the 
  position 
  

   of 
  the 
  electrodes. 
  When 
  the 
  kathode 
  is 
  at 
  the 
  aortic 
  end, 
  the 
  beat 
  begins 
  

   there 
  ; 
  when 
  at 
  the 
  auricular 
  end, 
  the 
  beat 
  begins 
  at 
  the 
  auricular 
  end, 
  

   and 
  in 
  that 
  case 
  differs 
  chiefly 
  from 
  the 
  normal 
  beat 
  in 
  being 
  more 
  or 
  

   less 
  confined 
  to 
  that 
  end. 
  When 
  the 
  electrodes 
  are 
  placed 
  at 
  the 
  sides 
  

   of 
  the 
  ventricle, 
  the 
  kathodic 
  side 
  beats 
  at 
  the 
  making, 
  and 
  the 
  anodic 
  

   at 
  the 
  breaking, 
  whichever 
  side 
  each 
  be 
  placed. 
  

  

  We 
  have 
  not 
  made 
  many 
  observations 
  on 
  the 
  auricle 
  alone, 
  but 
  have 
  

   seen 
  enough 
  to 
  satisfy 
  ourselves 
  that 
  the 
  same 
  law 
  holds 
  good 
  there 
  too, 
  

   that 
  the 
  making-beat 
  is 
  kathodic, 
  and 
  the 
  breaking 
  anodic. 
  

  

  We 
  need 
  hardly 
  point 
  out 
  the 
  remarkable 
  analogy 
  presented 
  by 
  these 
  

   facts 
  with 
  those 
  resulting 
  from 
  the 
  passage 
  of 
  a 
  constant 
  current 
  through 
  

  

  