Mediate  frcaisfusion  consists  in  intorpoeing  a  vessel  be-
tween the  supply  source  and  the  receptive  patient,  to
receive  the  blood,  whore  it  can  be  defibrinated,  if  that  bo
necessary.  As  a  rule,  now,  the  mediate  method  of  trans-
fusion is  limited  to  those  cases  requiring  defibrinated
blood.  The  vessel  receiving  the  blood  is  kept  warm  (100''
Fahr.),  and  the  blood  is  rapidly  whipped  up  as  it  fiows
until  every  bit  of  fibrin  is  coagulated.  The  fibrin  is
strained  out  by  ineana  of  a  cloth  strainer,  and  this  part
of  tho  process  must  bo  most  carefully  done,  for  should
any  solid  particles  of  the  fibrin  remain  in  the  mass  and  be
injected,  the  results  of  multiple  emboli  must  be  expected,
and  n  disaster  ine>'itably  occur.  Blood  from  a  humati
subject  or  from  an  animal  may  be  caught  in  a  suitable


132


BTPODERMATW  MEDJCATIOlf,


vessel,  and  then  transferred  to  the  patient  by  moans  of  a
syringe;  but  I  need  hardly  observe  that  such  procedures
arc  of  the  past  and  are  no  longer  justifiable.
Of  the  various  niethods  of  effecting  the  intravenous
injection  or  transfusion  of  blood,  there  can  be  no  doubt  of
the  superiority  of  the  immediate  method.  The  blood  of
a  healthy  subject,  of  the  same  sex  if  possible,  should  be
made  use  of  Direct  communication  between  the  vessels
of  the  donor  and  of  the  recipient  should  be  established,
id  a  quantity  of  blood  determined  by  the  conditions
present  should  be  passed  in.  In  cases  of  loss  of  blood
trom  any  cause,  the  amount  of  blood  given  need  not,  as  a
rule,  be  more  than  four  (4)  ounces,  and  very  often  half
that  quantity  will  suffice  to  put  a  very  different  eompleadon
on  the  appearances  of  danger  before  so  threatening.
