﻿142 
  

  

  Mr. 
  A. 
  H. 
  Garrod 
  on 
  the 
  

  

  Prop. 
  II. 
  The 
  length 
  of 
  the 
  interval 
  between 
  the 
  commencement 
  of 
  

   the 
  primary 
  and 
  the 
  dicrotic 
  rises 
  in 
  the 
  radial 
  artery 
  is 
  constant 
  for 
  any 
  

   given 
  pulse-rate, 
  and 
  varies 
  as 
  the 
  cube 
  root 
  of 
  the 
  length 
  of 
  the 
  pulse- 
  

   beat 
  — 
  being 
  found 
  from 
  the 
  equation 
  #/=47v 
  / 
  #, 
  where 
  #=the 
  pulse- 
  

   rate, 
  and 
  2/'=the 
  ratio 
  borne 
  by 
  the 
  above-named 
  part 
  to 
  the 
  whole 
  beat. 
  

  

  This 
  law 
  was 
  enunciated 
  in 
  the 
  paper 
  before 
  referred 
  to 
  as 
  read 
  before 
  

   this 
  Society 
  by 
  myself, 
  and 
  published 
  in 
  its 
  ' 
  Proceedings 
  ' 
  (vol. 
  xviii. 
  

   p. 
  351). 
  Since 
  that 
  paper 
  was 
  read 
  a 
  fresh 
  series 
  of 
  measurements 
  

   have 
  strongly 
  confirmed 
  its 
  accuracy, 
  and 
  practice 
  in 
  manipulation 
  has 
  

   diminished 
  my 
  limits 
  of 
  experimental 
  error 
  so 
  far 
  that 
  a 
  difference 
  of 
  

   5 
  per 
  cent, 
  from 
  the 
  calculated 
  results 
  is 
  rarely 
  found. 
  

  

  The 
  following 
  Table 
  contains 
  some 
  of 
  the 
  more 
  recent 
  results 
  and 
  one 
  

   or 
  two 
  more 
  careful 
  measurements 
  of 
  old 
  traces 
  : 
  — 
  

  

  

  Ratio 
  borne 
  by 
  sphyginosystole 
  to 
  \diole 
  beat, 
  as 
  

  

  Pulse-rate. 
  

  

  Found 
  

  

  Calculated 
  from 
  

  

  

  by 
  measurement. 
  

  

  equation 
  ay 
  =47^ 
  x 
  

  

  

  (approximately). 
  

  

  38 
  

  

  4-175 
  

  

  4-18 
  

  

  43-5 
  

  

  3-825 
  

  

  3-8 
  

  

  44-5 
  

  

  3-7875 
  

  

  3-75 
  

  

  56 
  

  

  3-29 
  

  

  3-22 
  

  

  58 
  

  

  3-195 
  

  

  3-135 
  

  

  59 
  

  

  3-185 
  

  

  3-0- 
  

  

  63 
  

  

  2-911 
  

  

  2-96 
  

  

  63-5 
  

  

  2-938 
  

  

  2-95 
  

  

  64 
  

  

  2-904 
  

  

  2-93 
  

  

  65 
  

  

  2-83, 
  2-821 
  

  

  2-9 
  

  

  67 
  

  

  2-825, 
  2-788 
  

  

  2-84 
  

  

  66-5 
  

  

  2-889 
  

  

  2-795 
  

  

  69 
  

  

  2-7 
  

  

  2-78 
  

  

  73 
  

  

  2-625 
  

  

  2-685 
  

  

  105 
  

  

  2-132 
  

  

  2-13 
  

  

  140 
  

  

  1-735 
  

  

  1-75 
  

  

  Prop. 
  III. 
  The 
  length 
  of 
  the 
  interval 
  between 
  the 
  primary 
  and 
  the 
  

   dicrotic 
  rises 
  follows 
  the 
  same 
  law 
  in 
  the 
  carotid 
  and 
  posterior 
  tibial 
  that 
  

   it 
  does 
  in 
  the 
  radial 
  artery. 
  

  

  That 
  such 
  is 
  the 
  case 
  as 
  far 
  as 
  the 
  femoral 
  and 
  posterior 
  tibial 
  

   arteries 
  are 
  concerned 
  is 
  shown 
  by 
  Dr. 
  Galabin 
  in 
  a 
  paper 
  " 
  On 
  the 
  

   Secondary 
  Waves 
  in 
  the 
  Pulse," 
  recently 
  published 
  (Journal 
  of 
  Anat. 
  

   and 
  Phys. 
  2nd 
  series, 
  No. 
  xiii.). 
  It 
  is 
  not 
  necessary, 
  in 
  proving 
  this 
  

   law, 
  to 
  undertake 
  any 
  large 
  series 
  of 
  measurements 
  ; 
  for 
  if 
  all 
  those 
  

   which 
  are 
  taken 
  agree 
  exactly 
  with 
  the 
  calculated 
  results 
  obtained 
  from 
  

   the 
  radial 
  equation, 
  the 
  probability 
  that 
  it 
  is 
  correct 
  is 
  almost 
  infinitely 
  

   great. 
  In 
  a 
  boy, 
  setat. 
  16, 
  whose 
  radial 
  pulse 
  was 
  previously 
  proved 
  to 
  

  

  