ME.  J.  LISTEE  ON  THE  EAELY  STAGES  OE  INFLAMMATION. 
697 
Considering  the  number  and  variety  of  the  functions  which  dhect  observation  has 
shown  to  be  suspended  by  irritants,  viz.  pigmentary  concentration  and  diffusion,  ciliary 
motion  and  nervous  action,  it  appears  probable  that  all  the  vital  processes  are  hable  to 
similar  temporaiy  arrest. 
Different  tissues,  however,  seem  to  differ  in  the  facility  with  which  they  are  affected 
by  m’itants.  The  pigment-cells  are  very  susceptible  to  theii’  influence,  as  is  indicated  by 
the  complete  paralysis  which  we  have  seen  to  be  produced  in  them  by  agencies  that  give 
rise  to  only  a minor  degree  of  inflammatory  congestion ; and  also  by  the  circumstance 
which  I have  often  observed  in  the  web  of  the  frog,  that,  as  in  the  choroid  coat  of  the 
human  eye,  they  become  absorbed  in  parts  which  have  been  injured,  having  been  deprived 
of  vitality  by  causes  which  inflicted  on  other  textures  only  a recoverable  lesion.  The 
epithehum-cells,  too,  are  very  sensitive  to  irritation,  exhibiting  its  results  more  rapidly 
than  can  be  accounted  for  merely  by  their  exposed  situation.  In  those  which  invest 
the  mucous  membrane  of  the  mouth,  the  cilia  with  which  they  are  provided  furnish 
the  opportunity  of  which  we  have  availed  ourselves,  of  observing  the  stage  of  suspension 
of  function  in  consequence  of  very  gentle  treatment ; and  though  the  epidermis  does 
not  admit  of  this,  it  shows  the  further  stage  of  loss  of  vitality  by  exfoliating  after  an 
amount  of  injury'  from  which  the  immediately  subjacent  tissues  readily  recover.  John 
Huntee  was  unquestionably  correct  in  the  opinion  that  the  elevation  of  the  cuticle  in 
vesication  depends  not  only  on  the  effusion  of  serum  beneath  it,  but  on  a primary 
separation  arising  “ h orn  a degree  of  weakness  approaching  to  a kind  of  death  in  the 
connexion  between  the  cuticle  and  cutis*.”  For  I find  that  in  an  amputated  limb  free 
from  blood,  although  no  effusion  of  serum  can  occur,  the  epidermis  becomes  speedily 
loosened  in  a part  to  which  an  iiTitant  is  apphed,  as  for  example,  in  a web  treated  with 
oil  of  turpentine,  whereas  it  remains  elsewhere  firmly  attached  for  days  if  the  weather 
be  cool. 
The  temporary  abolition  of  the  normal  relations  between  the  blood  and  the  tissues  in 
inflammatory  congestion  f,  must  be  added  to  the  list  of  instances  of  suspension  of  vital 
properties  by  mitation.  The  tissues  the  healthy  state  of  which  seems  most  hkely  to 
be  essential  to  that  of  the  \ital  fluid,  are  those  contiguous  to  it,  viz.  the  walls  of  the 
blood-vessels ; and  that  these  are  really  deprived  of  their  vital  endowments  during  in- 
flammation, seems  implied  by  the  character  of  the  material  which  is  transmitted  through 
them  in  that  condition.  For  we  have  seen  that  the  vascular  parietes  differ,  in  the  state 
of  health,  from  all  ordinary  sohds  in  being  destitute  of  any  attraction  for  the  fibrine, 
if  not  positively  repelhng  it  J,  and  that  this  is  probably  the  cause  of  the  merely  seroUs 
character  of  the  effusion  which  takes  place  in  mechanical  dropsy  depending  upon  ab- 
normal pressure  of  the  blood  within  healthy  vessels.  On  the  other  hand,  the  exudation 
of  the  liquor  sanguinis  in  its  integrity,  such  as  occurs  in  severe  inflammation,  cannot, 
I think,  be  satisfactorily  explained  by  the  mere  abnormal  pressure  of  the  blood  pro- 
* Works  of  JoHK  Hitntee,  Palmee’s  edition,  vol.  iii.  p.  349. 
t See  close  of  last  section.  J Vide  aniea,  p.  674. 
4 Y 2 
