On  reference  to  J'able  i  it  will  be  seen  that  haemolysis  was 
complete  up  to  a  concentration  of  0'045  per  cent,  of  quinine  bihydro- 
chloridCj  at  which  concentration  the  weight  of  red  cells  haemolysed 
was  iO‘4  times  that  of  the  quinine  salt  employed.  When  a  concen¬ 
tration  of  0'038  per  cent,  was  employedj  the  weight  of  red  cells  being 
now  137  times  that  of  the  quinine  salt  present  in  solution,  haemolysis 
was  only  partial,  and  on  extending  the  series  beyond  the  limit  given 
in  the  Table,  the  red  cells  were  found  not  to  be  appreciably  affected. 
The  transition  point  was  sharply  marked,  though  slight  variations  in 
the  rate  at  which  haemolysis  pi'oceeds  were  to  be  observed.  As  will 
appear  later  (cp.  Table  18),  in  different  samples  of  red  blood  cells, 
taken  from  the  same  (healthy)  individual,  similar  variations, 
inconsiderable  in  extent,  occur. 
In  the  more  concentrated  solutions  of  quinine  bihydrochloride 
haemolysis  proceeds  very  rapidly.  In  the  first  two  concentrations 
given  in  Table  i,  haemolysis  was  complete  within  an  hour,  and  in  the 
third  at  the  end  of  about  two  hours. 
A  second  series  of  experiments  (Table  2)  was  next  carried  out,  in 
which  the  concentration  of  the  quinine  salt  at  the  transition  point 
was  nearly  four  times  that  present  at  the  transition  point  of  the  first 
series.  In  these,  as  in  the  former  experiments,  the  transition  point 
Table  2.  Haemolysis  of  red  blood  cells  by  quinine  bihydrochloride,  in  nearly  four  times 
the  concentration  employed  in  Table  i .  Duration  of  experiment 
three  hours.  Temperature  37°  C. 
No.  of 
Experi¬ 
ment 
Composition  op  Mi.xture  of 
Red  Blood 
Cells  and 
Quinine  Solution 
Quinine  bihydrochloride  0*223  % 
Weight  of  wet  red  blood  cells  10*4 
Weight  of  quinine  salt  i 
1  o-i8S% 
13-0 
I 
O' '55% 
15-6 
O' ‘34% 
i8’2 
0-119% 
20*8 
I 
I 
Complete 
Complete 
A'larked 
Marked 
Slight 
(Marked]* 
(Partial) 
(SUght) 
(SUght) 
(Shght) 
2 
Complete 
Complete 
Marked 
Shght 
Slight 
(Complete) 
(A^arked) 
(Slight) 
(Slight) 
(Shghq 
3 
Complete 
Complete 
Complete 
Marked 
Slight 
(Complete) 
(Complete) 
(Shght) 
(Shght) 
(Shght) 
4 
Complete 
Complete 
Complete 
Marked 
Shght 
(Complete) 
(Complete) 
(Complete) 
(SUght) 
(Shght) 
5 
Complete 
Complete 
Complete 
Shght 
Shght 
(Complete) 
(Complete) 
(Marked) 
(Slight) 
(Shght) 
The  results  in  brackets  repreSent  the  action  of  quinine  bihydrochloride  when, 
instead  of  washed  red  cells,  equivalent  amounts  of  oxalated  blood  are  used. 
