If  the  solutions  employed  to  produce  haemolysis  are  compared  in 
respect  of  actual  percentage  of  haemolytic  agent  present,  it  will  be 
seen  that  hydrochloric  acid  is  by  far  the  most  potent  of  the  four 
made  use  of.  Sodium  hydrate  comes  close  to  hydrochloric  acid,  while 
quinine,  even  in  higher  concentrations,  is  a  relatively  feeble  haemolytic 
agent,  especially  if  employed  in  the  alkaloidal  state.  When, 
however,  the  maximum  weight  of  red  blood  cells  completely  haemo- 
lysed  is  compared,  not  with  the  actual  weight  of  haemolytic  agent 
present,  but  instead,  with  the  weight  of  red  blood  cells  haemolysed 
by  a  gramme-molecule  of  the  haemolytic  agent,  then  it  is  seen 
that,  molecule  for  molecule,  the  above  difference  largely  disappears, 
and  the  weight  of  wet  red  blood  cells  haemolysed  varies  m  the 
different  experiments  within  somewhat  narrow  limits.  The  results 
collected  together  in  Table  8  are  not,  however,  altogether  suitable 
for  close  comparison  since  the  molecular  concentrations  in  the 
different  series  are  not  identical.  In  order  to  permit  of  a  closer  com¬ 
parison,  three  additional  series  of  experiments  were  carried  out  with 
Table  9.  Haemolysis  of  wet  red  blood  cells  by  quinine  in  alkaloidal  state.  Duration 
of  experiment  three  hours.  Temperature  37'’  C. 
I  Composition  of  Mixture  of  Red  Blood  Cells  and  Quinine  Solution. 
No.  of  _ 
Experi¬ 
ment 
Quinine  (alkaloid)  0'0366  % 
Weight  of  wet  red  cells  2*4 
Weight  of  quinine  (alkaloid)  i 
0-0366  % 
I 
0*0366 
4*8 
^0 
- 
0 
6 
0*0366  pQ 
8-0 
I 
I 
Complete 
Complete 
Marked 
Partial 
Slight 
2 
Complete 
Complete 
Complete 
Marked 
Marked 
3 
Complete 
Complete 
Complete 
V’^ery 
Marked 
Partial 
4 
Complete 
Complete 
Complete 
Marked 
Slight 
s 
Complete 
Complete 
Complete 
•Almost 
complete 
Marked 
quinine  in  the  free  state,  hydrochloric  acid  and  sodium  hydrate,  each 
series  having  the  molar  concentration  0'00ii3,  and  thus  possessing 
the  concentration  of  the  transition  point  in  Table  i.  These  experi¬ 
ments  are  given  in  Tables  g,  lo  and  1 1,  and  the  concentrations  at  the 
transition  points  are  collected  together  in  Table  12.  No  further 
reference  is  required  at  this  point  to  Tables  g,  10  and  ii.  In  Table 
12  it  is  seen  that,  when  equimulecular  concentrations  are  employed, 
the  weight  of  red  blood  cells  completely  haemolysed  in  three  hours 
