8g 
to  20,  have  been  made.  Nolvvithstai’ding  the  incompleteness  of 
some  of  the  Fig-ures,  they  illustrate  the  wide  divergence  in  degree 
between  haemoglobinaemia  and  haemoglobiniiria  just  referred  to 
(Figs.  10,  13,  14,  16,  18,  20).  It  is  observable  that  a  fall  in  the 
percentage  of  dissolved  haemoglobin  in  the  blood  plasma  appears 
attended  by  a  corresponrling  fall  m  the  percentage  of  haemoglobin 
in  the  urine  (Figs.  10,  12,  13,  16,  18,  20),  just  as  occurs,  after  the 
initial  maximum  has  been  reached,  in  experimental  haemoglobinaemia 
(Figs.  8,  9,  10).  A  striking  point  of  difference  between  the  two  series 
of  ob.servations  is  that  in  experimental  haemoglobinaemia  the 
disappearance  of  haemoglobin  from  the  blood  plasma  appears  to  be 
more  rapid  than  in  blackwater  fever.  To  make  this  clear,  a  com- 
pari.son  in  respect  of  time  should  be  made  between  the  rate  of 
disappearance  of  haemoglobin  in  Figs.  2  to  9  (experimental  haemo¬ 
globinaemia)  and  that  occurring  in  Fig.s.  10,  12,  13,  14,  18  and  20 
(blackwater  fever). 
If  the  comparison  is  made  between  the  amount  of  haemoglobin 
injected  intravenously  and  that  reappearing  in  the  urine  (Table  35), 
it  is  seen  that,  in  our  experiments,  the  latter  was  only  a  small 
fraction  of  the  former  ranging  between  3  per  cent,  in  Experiment  2 
and  25  per  cent  in  Experiment  9.  Thus  the  hiked  haemoglobin  in 
the  rabbit’s  plasma  does  not  pass  through  the  kidneys  except  in  a 
relatively  small  amount,  the  greater  part  of  the  dissolved  haemoglobin 
being  dealt  with  in  the  body.  We  have  here  a  striking  parallel 
with  the  effect  of  injecting  egg  albumin  into  animals.  In  the  latter 
case  the  foreign  proteid  injected  is,  in  carnivora,  broken  up  in  the 
body,  the  nitrogen  it  contains  being  eliminated  as  urea  in  the  urine, 
and  only  a  small  fraction  escaping  through  the  kidneys  unchanged.* 
In  the  experiments  recorded  in  Table  35  repeated  examinations 
of  the  blood  plasma  were  made  so  that  it  becomes  possible  to  study 
the  rate  at  which  elimination  of  dissolved  haemoglobin  has  taken 
place,  'fhis  proceeded  rapidly  at  first  and  subsequently  progressed 
more  slowly.  In  one  Experiment  (4,  Table  35)  a  marked  irregularity 
in  the  rate  of  disappearance  occurred,  tire  percentage  of  dissolved 
haemoglobin  in  the  plasma  remaining  almost  unchanged  for  two 
*  t'riedemann  and  l.saac.  Zeitschr.  f.  exper.  V’atliologie.  tqo^,  lid.  i,  S.  i;i  u 
(|uoted  by  v.  Xoorden,  Pathology  of  Metabolism,  t.ondon.  1007,  \’ol.  j,  p.  pi. 
