ME.  J.  LISTEE  ON  THE  EAELT  STAGES  OF  INFLAMMATION. 
693 
tissue  thus  separated  from  its  connexions  was  in  an  exceedingly  delicate  condition,  and 
any  agent  used  for  arresting  the  action  of  the  ciha  was  very  apt  to  destroy  at  the  same 
time  the  vitality  of  the  cells.  Thus  when  the  object  was  warmed  by  placing  the  glass 
plate  on  a piece  of  iron  at  about  100°  Fahe.  for  half  a minute,  the  vibratory  movements 
were  arrested,  but  never  recovered,  and  in  a short  time  the  cells  swelled  up  by  endos- 
mose.  It  appeared  probable  that  the  tissue  had  suffered  during  the  time  required  for 
the  cooling  of  the  glass;  and  in  order  to  avoid  this,  and  also  prevent  the  object-glass 
becoming  obscured  by  vapour  from  the  warm  water  condensing  upon  it,  the  epithelium 
was  placed  between  two  slips  of  thin  covering  glass,  kept  from  too  close  approximation 
by  fragments  of  the  same  material  interposed,  the  whole  forming  a layer  so  thin  that  it 
would  be  rapidly  heated  if  any  hot  body  were  placed  in  its  vicinity,  and  cool  as  quickly 
on  its  removal.  A small  cautery  iron,  with  a bulbous  extremity  about  as  big  as  a hazel- 
nut, just  too  hot  to  bear  in  contact  with  the  finger,  was  now  put  behind  the  stage  of  the 
microscope,  within  about  three-quarters  of  an  inch  of  the  object,  the  diaphragm  plate 
having  been  removed  to  afford  room  for  this  being  done  without  interfering  with  the 
fight  sent  up  by  the  reflector.  The  result,  which  I watched  from  the  first,  was  the  same 
that  I had  once  before  observed  from  the  very  gentle  application  of  heat  to  a portion  of 
a frog’s  tongue,  viz.  primary  increase  in  the  action  of  the  cilia  which  had  previously  been 
languid  *,  but  which,  within  ten  seconds  of  the  approximation  of  the  cautery,  were  moving 
with  great  rapidity,  and  continued  to  do  so  for  about  twenty-five  seconds,  at  the  expira- 
tion of  which  their  motion  was  seen  to  be  diminishing,  and  after  another  minute  and  a 
half  it  was  considerably  more  languid  than  at  the  beginning  of  the  experiment.  The 
cautery  being  now  removed  was  found  to  be  much  cooled  though  still  warm,  and  its 
withdrawal  did  not  afiect  the  cilia,  which  still  remained  much  in  the  same  state  after 
the  lapse  of  eight  minutes.  I now  repeated  the  experiment  upon  a fresh  portion  of 
epithelium,  but  this  time  used  the  cautery  red-hot,  placing  it  about  2 inches  behind  the 
object:  no  sooner  had  this  been  done  than  the  action  of  the  cilia  became  excessively 
increased,  but  this  did  not  continue  for  more  than  five  seconds,  when  they  became  per- 
fectly motionless.  The  hot  iron  was  now  at  once  withdrawn,  but  the  cilia  under  special 
observation  did  not  recover.  In  other  situations  in  the  same  specimen,  however,  move- 
ments were  observed  in  the  course  of  the  following  minute,  and  it  was  still  continuing 
seven  minutes  later,  when  a part  having  been  brought  into  the  field  where  there  were 
two  considerable  groups  of  cells  in  moderate  activity,  the  cautery  was  again  applied  at  a 
distance  of  about  2^  inches.  The  motions  of  the  cilia  immediately  became  distinctly 
increased,  but,  as  in  the  former  case,  this  condition  gave  place  in  five  seconds  to  unir 
versal  quiescence.  The  iron  was  then  removed,  and  on  re-examination  after  three 
minutes,  the  cilia  were  again  moving,  though  in  a somewhat  languid  manner  in  both 
* Professor  Webee  of  Leipsig  observed  several  years  ago  that  the  action  of  cilia  upon  epithelium  cells 
removed  from  the  human  nostril  was  increased  by  gentle  warmth,  but  retarded  by  cold.  In  that  case  the 
elevated  temperature  was  natural  to  the  tissue,  and  might  be  supposed  to  operate  by  restoring  it  to  its 
normal  conditions.  In  the  cold-blooded  reptile,  however,  the  accelerated  movement  under  the  influence 
of  heat  has,  of  course,  a very  different  significance. 
