﻿1875.] 
  Dr. 
  J. 
  Williams 
  on 
  the 
  Discharge 
  of 
  Ova, 
  fyc. 
  439 
  

  

  appears 
  to 
  be 
  so 
  closely 
  connected 
  with 
  the 
  existence 
  of 
  an 
  undue 
  amount 
  

   of 
  pressure. 
  In 
  fig. 
  II. 
  I 
  find 
  it 
  rather 
  difficult 
  to 
  think 
  that 
  the 
  degree 
  

   of 
  pressure 
  did 
  not 
  in 
  some 
  way 
  modify 
  the 
  form 
  of 
  the 
  tracing. 
  Of 
  

   course 
  if, 
  as 
  is 
  most 
  probable, 
  reversal 
  of 
  the 
  tracing 
  depends 
  solely 
  on 
  the 
  

   cause 
  I 
  have 
  pointed 
  out, 
  and 
  can 
  be 
  produced 
  in 
  no 
  other 
  way, 
  no 
  pos- 
  

   sible 
  effect 
  can 
  be 
  attributed 
  to 
  any 
  alteration 
  of 
  the 
  spring-pressure, 
  as 
  

   the 
  spring 
  is 
  dissociated 
  from 
  the 
  cause 
  of 
  motion. 
  

  

  The 
  only 
  notice 
  I 
  have 
  found 
  in 
  Marey's 
  work 
  of 
  any 
  thing 
  like 
  such 
  

   traces 
  as 
  I 
  have 
  described 
  occurs 
  at 
  p. 
  282, 
  where 
  he 
  says 
  : 
  — 
  " 
  Type 
  84 
  

   presents 
  a 
  singular 
  peculiarity, 
  the 
  rebound 
  has 
  not 
  had 
  time 
  to 
  finish 
  

   before 
  the 
  arrival 
  of 
  a 
  fresh 
  pulsation 
  ; 
  the 
  result 
  is 
  a 
  form 
  which 
  might 
  

   be 
  taken 
  for 
  a 
  tracing 
  inverted 
  (ecrit 
  en 
  sens 
  inverse) 
  ; 
  but 
  this 
  depends 
  

   only 
  on 
  the 
  phenomena 
  of 
  dicrotism 
  not 
  having 
  had 
  time 
  to 
  work 
  them- 
  

   selves 
  out 
  (s'accomplir) 
  between 
  two 
  successive 
  pulsations." 
  

  

  The 
  circumstance 
  that 
  the 
  aortic 
  notch 
  is 
  preserved 
  during 
  the 
  arterial 
  

   systole 
  taking 
  place 
  under 
  such 
  altered 
  circumstances 
  is 
  noteworthy, 
  and 
  

   shows 
  the 
  essentiality 
  of 
  this 
  event. 
  It 
  was 
  remarking 
  the 
  presence 
  of 
  

   this 
  notch 
  which 
  first 
  made 
  me 
  suspect 
  that 
  the 
  sloping 
  ascent 
  of 
  the 
  

   inverted 
  tracing 
  was 
  not 
  equivalent 
  to 
  the 
  ascent 
  of 
  the 
  ordinary. 
  

  

  The 
  chief 
  practical 
  lesson 
  to 
  be 
  derived 
  from 
  the 
  foregoing 
  statements 
  

   is, 
  that 
  we 
  need, 
  in 
  using 
  the 
  Sanderson-Marey 
  sphygmograph, 
  to 
  be 
  very 
  

   careful 
  that 
  the 
  brass 
  plate 
  is 
  so 
  placed 
  as 
  not 
  to 
  rest 
  upon 
  the 
  artery. 
  

   If 
  the 
  artery 
  is 
  pressed 
  on 
  by 
  the 
  spring 
  and 
  the 
  brass 
  plate, 
  the 
  pres- 
  

   sure 
  of 
  the 
  latter 
  being 
  materially 
  the 
  greatest, 
  the 
  amplitude 
  of 
  the 
  

   tracing 
  may 
  be 
  factitiously 
  increased. 
  If 
  the 
  brass 
  plate 
  alone 
  press 
  on 
  

   the 
  artery 
  the 
  tracing 
  will 
  be 
  reversed. 
  I 
  think 
  the 
  arch 
  in 
  the 
  middle 
  

   of 
  the 
  plate 
  should 
  be 
  much 
  wider 
  than 
  it 
  is 
  often 
  made. 
  

  

  III. 
  " 
  Note 
  on 
  the 
  Discharge 
  of 
  Ova, 
  and 
  its 
  relation 
  in 
  point 
  of 
  

   Time 
  to 
  Menstruation." 
  By 
  John 
  Williams, 
  M.D. 
  Loncl., 
  

   Assistant 
  Obstetric 
  Physician 
  to 
  University 
  College 
  Hospital. 
  

   Communicated 
  by 
  Dr. 
  Sharpey, 
  F.R.S. 
  Received 
  April 
  7, 
  

   1875. 
  

  

  It 
  is 
  a 
  recognized 
  fact 
  in 
  physiology 
  that 
  ova 
  are 
  discharged 
  in 
  con- 
  

   nexion 
  with 
  the 
  menstrual 
  function, 
  but 
  it 
  is 
  uncertain 
  at 
  what 
  time 
  in 
  

   the 
  course 
  of 
  the 
  month 
  the 
  separation 
  takes 
  place. 
  It 
  is 
  generally 
  

   understood 
  to 
  occur 
  towards 
  the 
  end 
  of 
  the 
  discharge, 
  or 
  immediately 
  

   after 
  its 
  cessation. 
  I 
  have, 
  however, 
  reason 
  to 
  believe, 
  from 
  observations 
  

   made 
  in 
  several 
  subjects, 
  that 
  such 
  is 
  not 
  the 
  case, 
  but 
  that 
  it 
  takes 
  place 
  

   before 
  the 
  appearance 
  of 
  the 
  monthly 
  flow 
  with 
  which 
  it 
  is 
  connected. 
  

   The 
  cases 
  which 
  have 
  come 
  under 
  my 
  observation 
  fall 
  into 
  four 
  series, 
  

   as 
  follows 
  : 
  — 
  

  

  A. 
  Cases, 
  six 
  in 
  number, 
  in 
  which 
  a 
  Graafian 
  follicle 
  had 
  been 
  matured 
  

   and 
  actually 
  ruptured. 
  

  

  