ME.  J.  LISTEE  OJf  THE  EAELT  STAGES  OF  INFLAMMATION. 
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sequently  presenting  themselves  in  somewhat  abnormal  proportion.  I have  often  ob- 
sened  the  complete  absence  of  adhesiveness  of  the  white  corpuscles  within  the  vessels 
in  health,  and  have  also  watched  them  gradually  assume  a tendency  to  adhere,  in  conse- 
quence of  repeated  mild  applications  of  chloroform  to  a web  in  which  they  previously 
exhibited  no  such  disposition  whatever.  As  the  irritation  increases,  the  vessels  become 
crusted  wdth  them  often  to  a remarkable  degree,  and  occasionally  large,  colourless, 
agglomerated  masses  of  them,  just  such  as  are  seen  in  blood  di’awn  from  the  body,  may 
be  observed  to  roll  along  the  large  veins  among  the  slowly  moving  and  very  numerous 
red  discs.  I once  watched  the  formation  of  one  of  these  masses*  as  a delta-like  accu- 
mulation at  the  place  where  a considerable  venous  branch  opened  into  a main  trunk,  the 
calibre  of  which  was  nearly  entirely  occupied  by  it  before  it  was  swept  away  by  the  current. 
As  a general  rule,  the  white  corpuscles  when  adhering  do  not  arrest  the  progress  of  the 
red  ones,  which  are  often  seen  to  pass  through  very  small  intervals  among  the  colourless 
masses ; not  unfrequently,  however,  red  corpuscles  are  stopped  in  their  course  and  adhere 
among  the  white  ones,  and  sometimes,  especially  in  young  frogs,  capillaries  become  ob- 
structed throughout  their  entire  length  by  white  corpuscles  alone,  and  when  this  is  the 
case,  they  are  apt  to  escape  notice  from  the  inconspicuous  character  of  their  contents. 
The  adhesiveness  of  the  white  corpuscles,  as  of  the  red  ones,  is  limited  to  the  part 
irritated.  A veiy  good  example  of  this  presented  itself  on  one  occasion  when  a minute 
drop  of  chloroform  was  applied  to  a small  part  of  a healthy  web  so  as  to  induce  full  dila- 
tation of  the  arteries  and  great  excess  of  corpuscles,  but  without  absolute  stagnation.  It 
happened  that  the  part  affected  was  supplied  with  blood  by  the  branches  coming  from 
one  side  of  a principal  artery;  the  main  trunk  being  seated  just  about  the  limit  between 
the  irritated  area  and  the  healthy  region,  the  adjacent  part  of  which  received  supply 
from  the  branches  of  the  vessel  on  the  other  side.  The  latter  showed  no  appearance  of 
adhering  white  corpuscles,  nor  did  the  capillaries  which  were  fed  by  them ; but  those  of 
the  irritated  part,  though  springing  from  the  same  trunk,  were  remarkably  encrusted 
with  them  from  their  origin  to  their  minutest  ramifications  within  the  area,  while  the 
capillaries  and  veins  in  the  same  part  were  similarly  affected.  This  striking  appearance 
continued  for  hours  after  the  chloroform  had  been  applied,  successive  fully  formed  white 
corpuscles  adhering  as  they  flowed  in  from  the  trunk,  being  evidently  affected  secondarily 
to  the  change  induced  by  the  chloroform  in  the  tissues  of  the  web. 
Thus  the  affection  of  the  white  corpuscles  of  the  blood  in  an  irritated  part  is  in  all 
respects  strictly  parallel  to  that  of  the  red  discs,  while  the  greater  adhesiveness  of  which  the 
former  are  capable,  renders  the  facts  regarding  them  more  obvious  and  unmistakeable. 
Being  desirous  to  verify  the  results  derived  from  the  frog  by  observations  upon  mam- 
maha,  in  which  the  aggregation  of  the  red  corpuscles  assumes  a much  more  striking  ap- 
pearance, I examined  the  wings  of  two  small  bats.  In  the  first  specimen,  the  corpuscles, 
both  red  and  white,  exhibited  decided  adhesiveness  within  the  vessels,  the  web  being  appa- 
rently in  a state  of  irritation  from  injuries  which  the  animal  had  sustained.  In  the  other 
there  was  also  some  adhesiveness  in  the  part  that  first  met  my  eye,  the  red  discs  tend- 
* This  observation  was  made  subsequently  to  the  reading  of  the  paper. 
MDCCCLVIII.  4 T 
