90 
hours.  The  reaction  rale  lormula  for  bunolecular  and  multimolecular 
reactions  does  not  apply  to  these  experiments.  The  rate  of 
disappearance  of  haemoglobin  follows,  however,  fairly  closely  a 
monomolecular  course,  as  the  values  of  K,  calculated  in  the  fourth 
column  of  Table  37,  show.  This  will  be  further  evident  when  the 
percentages  calculated  in  the  last  column  of  this  table  are  compared 
with  those  determined  by  experiment,  in  the  third  c-olumn.  ft  thus 
becomes  possible  to  calculate  the  haemoglobinaemia  present 
immediately  after  injection,  and  from  this  the  total  volume  of  blood 
in  the  animals  at  the  beginning  of  the  experiment  can  be  determined 
(Col.  3,  Table  35).  When  the  dissolved  haemoglobin  has  been 
reduced  to  less  than  10  per  cent,  of  its  original  amount,  further 
destruction  proceeds  with  considerable  and  rapidly  increasing 
slowness.  The  rate  of  disap})earance  thus  is  similar  to  that  observed 
in  Table  17.  Contrary  to  what  would  be  expected  there  seems  to 
be  considerable  difficulty  in  removing  the  last  traces  of  haemogloliin 
from  the  plasma.  It  may  here  be  observed  that  rabbits  which  have 
been  injected  with  dissolved  haemoglobin  show  small  percentages  of 
haemoglobin  in  their  blood  plasma  for  many  days  afterwards,  in  this 
respect  resembling  human  beings  and  differing  from  normal  rabbits. 
The  curious  change  in  the  rate  of  disappearance  of  haemoglobin, 
exhibited  in  Experiment  4,  in  which  the  percentage  of  haemoglobin 
remained  almost  unaltered  between  the  hundred  and  thirty-fourth 
and  the  two  hundred  and  fifty-seventh  minutes,  is  difficult  to  interpret 
The  rate  of  disappearance  of  haemoglobin  is  relatively  slow  in 
Experiments  2,  5  and  g,  in  which  the  value  of  K  is  0'00I05  ;  in  the 
other  experiments  K  ranges  between  0‘0029  and  O'OO^C.  These 
values  stand,  except  in  Experiment  9,  in  a  definite  relation  to  the 
age  of  the  animal  used  for  experiment ;  in  Experiments  2,  5  and  9 
the  animals  employed  were  young,  and  the  total  blood  was,  as  already 
mentioned,  about  one-tenth  of  the  body  weight. 
The  question  arises,  does  the  disappearance  of  the  dissolved 
haemoglobin  depend  upon  decomposition  occurring  in  the  blood 
plasma  ?  This  enquiry  cannot  be  directly  settled  by  experiment  in 
vitro  with  the  non-oxalated  plasma  of  the  rabbit,  owing  to  the 
rapidity  with  which  clotting  takes  place.  In  Table  38  are  recorded 
some  observations  made  with  oxalated  plasma,  and  with  plasma 
defibrinated  by  shaking  with  glass  beads.  In  Experiment  i  the 
