47 
ig,  Table  24,  in  which  the  ratio  of  the  two  determinations  is 
respectively  i'36  :  i,  r37  :  i  and  i'24  :  i,  then  a  close  comparison 
becomes  difficult,  since  it  is  no  longer  possible  to  state  the  ratio  of 
Tahlf.  r.  Haemolysis  of  red  blood  cells  by  quinine  bihydrochloride,  dissolved  in  o'q 
per  cent.  NaCl  solution.  Duration  of  experiment  three  hours.  Temperature 
Nn.  of 
Experi¬ 
ment 
Composition  of  Mixturk  of  Red  Rt.ood 
Cells  and 
Quinine  Solu 
rioN, 
Quinine  bibydrochloride  o*o8o% 
Weip(ht  of  wet  red  blood  cells  yz 
Weight  of  quinine  salt  i 
0-065  % 
T5 
I 
0-054  '’0 
36-5 
1 
0-045  % 
10*4 
1 
I 
12,  .oj  - 
0 
6 
I 
Complete 
Complete 
Complete 
1  Complete 
Partial 
2 
Complete 
Complete 
Complete 
i  Complete 
Marked 
3 
Complete 
Complete 
Complete 
Complete 
Partial 
4 
Complete 
Complete 
Complete 
1  Complete 
Partial 
5 
Complete 
Complete 
Complete 
Complete 
Partial 
the  red  cells  to  quinine  so  precisely  as  could  be  desired.  It  is 
therefore  evident  that  an  extremely  close  comparison  of  the  action 
of  quinine  on  red  cells  in  health  and  in  blackwater  fever  cannot  be 
made.  The  series  of  increments  adopted  in  Tables  r  and  24  appear 
to  be  the  smallest  which  can  conveniently  be  chosen.  Blackwater 
fever  patients  are  frequently  anaemic,  and  it  will  be  noticed  that  the 
haemoglobin  of  the  red  cells  was  generally  altered  in  the  direction  of 
an  increase  in  the  amount  per  unit  volume  of  red  cells.  In 
Experiment  4,  Table  24,  although  the  direct  haemoglobinometer 
reading  of  the  blood  was  24,  the  normal  reading  being  100,  this  ratio 
was  scarcely  affected,  being  O'gs. 
In- Table  24  the  result  of  eighteen  observations  of  the  haemolysis 
of  red  cells  by  quinine  in  blackwater  fever,  and  two  observations  in 
malaria,  is  given.  For  the  sake  of  easy  reference,  Table  i  is  repeated. 
In  the  latter  Table  the  transition  point  is  well  defined,  and  is  seen  to 
be  reached  with  a  concentration  of  0'045  per  cent,  of  quinine  bihydro^ 
chloride  and  a  ratio  of  red  cells  (by  weight)  to  quinine  bihydrochloride 
of  10-4  :  I.  In  Table  24  the  same  result  is  obtained  in  nearly  every 
case,  the  exceptions  being  Experiments  3,  4,  12,  ig  and  20,  in  all  of 
which  haemolysis  proceeded  at  a  slightly  slower  rate  than  usual. 
Since  occasional  variations  are  also  met  with  under  normal  conditions, 
(cp.  Tables  2,  3,  5,  6,  7,  g,  ii),  it  follows  that  within  the  limits  of 
