[ 607  ] 
XXIX.  An  Inquiry  regarding  the  ])arts  of  the  Nervous  System  which  regulate  the  con- 
tractions of  the  Arteries.  By  Joseph  Lister,  Esq..,  F.R.C.S.  Eng.  and  Edin., 
Assistant  Surgeon  to  the  Royal  Infirmary,  Edinburgh.  Communicated  by  Dr.  Sharpey, 
Sec.  R.S. 
Eeceived  June  18, — Eead  June  18,  1857*. 
Great  light  has  been  thrown  in  recent  times  upon  the  nature  of  the  influence  exercised 
over  the  blood-vessels  by  the  nervous  system.  In  1852  it  was  shown  by  M.  Bernard 
that  division  of  the  sympathetic  nerve  in  the  neck  of  a cat,  or  other  mammalian,  was 
followed  by  turgescence  of  the  blood-vessels  of  the  ear,  and  increased  heat  of  that  part 
and  of  the  whole  side  of  the  face,  together  "with  contraction  of  the  pupil.  Early  in  the 
following  year  Mr.  Augustus  Waller  performed  the  converse  experiment  of  galvanizing 
the  sympathetic  above  the  point  where  it  had  been  cut  or  tied,  with  the  very  striking 
result  of  rapid  subsidence  of  the  turgescence  of  the  vessels,  and  fall  of  the  temperature 
of  the  face ; while  the  pupil  became  so  extremely  large,  as  to  imply  that  the  dilating 
fibres  of  the  his  were  thrown  into  a state  of  energetic  contraction  f. 
From  these  experiments  it  appeared  to  follow  pretty  clearly  that  the  sympathetic 
nerve  in  the  neck  presides  over  the  contraction  of  the  vessels  of  the  face,  which, 
becoming  relaxed  and  dilated  when  the  influence  of  the  nerve  was  removed  by  its 
division,  allowed  the  blood  to  flow  through  them  in  larger  mass  than  before ; but  on  the 
other  hand,  when  excited  to  extreme  constriction  by  the  galvanic  stimulus  applied  to 
the  nerv'e,  permitted  but  little  blood  to  pass.  This  conclusion  appears  to  be  confirmed 
by  the  observation  since  made  by  Brown-Sequard,  that  the  elevation  of  temperature 
which  occurs  in  Bernard’s  experiment  is  never  greater  than  is  to  be  accounted  for  by 
the  increased  mass  of  warm  blood  which  must  be  sent  through  the  part,  on  the  hypo- 
thesis that  the  turgescence  of  the  vessels  is  simply  the  result  of  their  dilatation.  It  was 
further  shown  by  Messrs.  Waller  and  Budge,  that  the  same  region  of  the  spinal  cord 
which  they  had  previously  ascertained  to  preside  over  dilatation  of  the  pupil,  namely, 
the  part  included  between  the  last  cervical  and  third  dorsal  vertebrse,  also  regulated  the 
vessels  of  the  face.  When  that  part  of  the  cord  was  removed,  turgescence  of  those 
vessels  occurred ; but  galvanizing  the  anterior  roots  of  the  spinal  nerves  proceeding  from 
* This  paper,  and  that  on  the  Pigmentary  System  of  the  Prog,  were  read  as  supplements  to  the  Essay  on 
the  Early  Stages  of  Inflammation  which  succeeds  them.  The  author  has  since  extended  his  investigations 
into  the  subject  of  the  present  memoir,  in  accordance  with  a recommendation  from  the  Council,  and  tlie 
results  have  been  incorporated  into  the  text,  all  new  matter  thus  introduced  being  indicated  as  such  either 
by  date  or  by  note  at  the  foot  of  the  page. 
t Comptes  Eendus,  vol.  xxxvi.  p.  378. 
MDCCCLVIII.  4 L 
