1  42 
the  nnnc  was  roo4  or  less,  for  in  urine  of  or  below  this  specif 
^^ravily  laking  occurs  almost  immediately  when  red  cells  are  acldecl 
If  the  urine  is  of  the  specific  gravity  roof)  to  roo8,  laking  occurs  willi| 
more  or  less  slowness,  and  in  urine  whose  specific  gravity  is  roiosi 
upwards,  laking  does  not  occur  to  any  considerable  extent.  If  renaij 
haemoiThage  were  the  cause  of  the  haemoglobinuria  of  blackwalej 
fever  the  site  of  the  haemorrhage  would  necessarily  be  the  glomenil:' 
of  the  kidneys,  for  only  here  could  the  blood  leadily  find  its  way  inti, 
the  urine,  while  on  the  other  hand  marked  interstitial  haemorrhag!j 
would  be  ordinarily  readily  discoverable  post-mortem,  which  is  m| 
the  case.  Furthermore,  if  renal  haemorrhage  were  the  cause  oftlit| 
haemoglobinuria  of  blackwater  fever,  then  the  haemoglobinaemii 
observable  in  this  condition  w'ould  be  a  secondary  conseciuence  ofti 
renal  haemorrhage,  and  would  be  explicable  only  on  the  assumptioe 
that  some  of  the  dissolved  haemoglobin  was  taken  up  by  the  rcni^ 
epithelium  and  passed  on  into  the  blood  stream. 
On  the  other  hand,  the  experiments  made  upon  rabbits  (Table  35] 
in  which  the  effect  of  simple  haemoglobinacmia,  [iroduced  with  tlij 
animal’s  own  haemoglobin,  was  studied,  taken  in  conjunction  W14 
the  circumstance  that  haemoglobinaemia  is  present  during  lli^ 
haemoglobinuria  of  blackwater  fever,  suggests  very  strongly  that 
this  affection  the  primary  condition  is  haemoglobinaemia. 
It  remains  to  be  considered,  therefore,  how  far  these  tiij 
alternative  hypotheses,  namely,  primary  glomerular  haemorrhage  mi 
primary  haemoglobinaemia,  are  capable  of  accounting  for  4 
phenomena  of  blackwater  fever,  and,  if  possible,  to  decide  which 
the  two  is  concerned  in  giving  origin  to  blackwater. 
The  extent  to  which  the  theory  of  a  primary  haemoglobinaeni^ 
is  in  harmony  with  the  various  facts  already  ascertained  respectinj 
blackwater  fever  will  be  fiist  considered,  and  then  the  remain^ 
hypothesis  will  be  criticised  in  the  same  manner.  Owing  to  li^ 
importance  of  this  enquiry,  it  will  be  dealt  with  at  some  length. 
1.  From  the  experiments  made  on  rabbits  (Table  35)  h 
evident  that  a  primary  haemoglobinaemia  reaching  to  as  much 
o'g5  per  cent,  of  haemoglobin,  such  as  occurs  in  blackwater  fe'' 
would  be  attended  with  the  appearance  of  haemoglobin  in  the  iin«i 
Our  results  do  not  enable  us  to  say  how  large  the  maxinii^, 
percentage  of  haemoglobin  in  the  blood  plasma  in  blackwater  fc'l 
