ME.  J.  LISTEE  ON  THE  EAELY  STAOES  OF  INFLAMMATION. 
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their  characters  were  precisely  similar  These  are  examples  of  what  very  numerous 
observations  have  tended  to  establish,  namely,  that  on  the  one  hand  the  red  corpuscles  in 
the  vessels  of  a perfectly  healthy  part  are  free  from  adhesiveness ; and  on  the  other  hand, 
the  adhesiveness  which  they  acquire  in  inflammatory  congestion,  though  varying  in  pro- 
portion to  the  degree  of  irritation,  is  never  greater  than  occurs  in  the  blood  of  a healthy 
part  when  withdrawn  from  the  body. 
These  conclusions,  if  correct,  represent  cardinal  truths,  both  in  physiology  and  patho- 
logy, implying  relations  of  the  tissues  to  the  blood  both  in  health  and  in  disease,  such 
as  have  never  before  been  demonstrated,  or,  I beheve,  even  suspected.  I was  therefore 
anxious  to  submit  them  to  further  test,  particularly  as  it  is  by  no  means  easy  to  estimate 
the  precise  degi*ee  of  adhesiveness  possessed  by  the  red  corpuscles  within  the  vessels ; 
and  it  occurred  to  me  that  one  means  of  doing  this  would  be  to  compare  specimens  of 
blood  shed  from  inflamed  and  healthy  parts  of  the  same  individual ; for  if  my  deductions 
were  sound,  the  adhesiveness  of  the  red  corpuscles  ought  to  be  neither  more  nor  less  in 
the  one  case  than  in  the  other. 
\Yith  this  view  I made  the  following  experiments.  Having  carefully  examined  the 
blood  of  a large  frog,  di'awn  from  a subcutaneous  vein  of  the  abdomen,  so  as  to  become 
quite  familiar  with  the  appearance  of  its  corpuscles,  I applied  mustard  to  the  whole 
smTace  of  one  foot  till  inflammatory  congestion  had  been  fully  developed  in  it,  and  then, 
amputating  both  feet  at  the  ankle-joint,  squeezed  out  blood  from  each  upon  a glass 
plate,  and  carefully  examined  both  specimens,  without  being  able  to  detect  the  slightest 
difference  between  them.  The  other  experiments  with  this,  object  were  performed  on 
the  human  subject.  In  one  of  these  I applied  a portion  of  moistened  mustard  to  the 
dorsal  aspect  of  the  last  phalanx  of  one  of  my  fingers,  and  retained  it  there  for  five 
hours,  with  the  exception  of  occasional  removal  for  the  purpose  of  drawing  blood  for 
examination.  By  the  conclusion  of  the  time  mentioned,  the  skin  on  which  the  mustard 
had  been  placed  was  in  a very  decided  state  of  inflammation,  being  red,  swollen  and 
painful,  and  the  redness  at  one  spot  disappearing  imperfectly  on  pressm’e,  and  returning 
languidly  after  its  removal.  A very  minute  drop  of  blood  drawn  with  a fine  needle  from 
the  sm’face  of  the  most  inflamed  part  was  then  compared  with  a drop  of  similar  size 
from  another  finger,  but  no  difference  could  be  detected  between  them,  nor  had  any 
been  obseiTed  in  previous  similar  comparisons.  On  another  occasion,  a friend  of  mine 
suffering  fr'om  intense  inflammation  of  the  back  of  the  hand,  in  consequence  of  the  irri- 
tation of  offensive  pus,  permitted  me  to  take  blood  with  a needle  from  the  most  severely 
affected  part,  and  also  from  one  of  the  fingers,  which  was  healthy.  I compared  drops 
from  the  two  sources  several  times  very  carefully  with  each  other  by  means  of  the  micro- 
* In  performing  experiments  upon  a foot  in  which  the  circulation  has  been  arrested,  it  is  important  to 
guard  against  a deception  apt  to  arise  from  the  direct  action  of  an  irritant  upon  the  blood  in  the  vessels. 
Thus,  if  a drop  of  chloroform  of  considerable  size  be  applied  to  a web  under  those  circumstances,  it  will  soak 
in  and  produce  its  chemical  effects  upon  the  blood,  the  earliest  of  which  is  complete  abolition  of  adhesive- 
ness in  the  corpuscles. 
