io 
It  may  here  be  pointed  out  that  in  these  experiments  quinine  is 
present  in  colloidal  solution,  and  that  film  formation  on  the  hqind-air 
surface  of  the  quinine  solution  is  very  marked.  If  such  a  solution  is 
several  times  poured  from  one  vessel  to  another  a  large  amount  of 
the  quinine  present  may  be  separated  out,  and  the  concentration  ol 
the  alkaloid  correspondingly  lowered.  It  is,  therefore,  necessary  to 
avoid  as  far  as  possible  any  procedure  likely  to  cause  such  separation 
of  quinine.  After  the  admixture  of  the  solution  of  alkaloidal  quinine 
with  emulsion  of  red  blood  cells,  the  tendency  to  film  formation  is  no 
longer  observable. 
3.  Action  of  hydrochloric  acid  on  red  bloqd  cells. 
The  quinine  salt  employed  in  the  experiments  recorded  in  Tables 
1  to  3,  when  dissolved  in  water,  becomes  m  part  hydrolysed  and  forms 
an  acid  solution.  It  becomes  therefore  desirable  to  institute  a 
comparison  between  the  action  of  hydrochloric  acid  and  of  quinine 
upon  red  blood  cells.  In  this  connection,  in  order  to  admit  of  a  wider 
range  of  comparison,  the  action  of  free  alkali  was  also  determined 
and  may  thus  be  contrasted  with  that  of  quinine  in  the  form  of  free 
base.  The  latter  experiments  are  given  in  the  succeeding  section. 
Table  6.  Haemolysis  of  red  blood  cells  by  hydrochloric  acid  dissolved  in  0-9  per  cent. 
NaCl  solution.  Duration  of  experiment  three  hours.  Temperature  37°  C. 
Composition  of  Mi.xturl  or  Red  Blood  Cells  and  Hydrochloric  Acid  Solution. 
No.  of 
Experi¬ 
ment 
Hydrochloric  acid  0*0137%! 
Weight  of  wet  red  cells  146 
Weight  of  hydrochloric  acid  i  ^ 
0-0114% 
182  . 
I 
o*oo<)8  “/(,  1 
2!g 
I 
o-oo86  %  1 
yj  i 
1 
0*0076 
292 
I 
- i 
I 
1 
Complete  ' 
Complete 
.  Partial 
Slight  i 
Slight 
2 
C'omplete 
Complete 
Partial 
Slight 
Slight 
3 
Complete 
Comnlcte 
Marked 
Slight  1 
slight 
4 
Complete 
Complete 
Complete 
Slight 
Slight 
5 
Complete 
1 
j  Complete 
Marked 
Slight 
Slight 
The  experiments  made  with  hydrochloric  acid,  which  was  dissolved 
in  O'Q  per  cent,  sodium  chloride  solution,  so  as  to  be  isotonic  with  blood 
plasma,  are  given  in  Table  6.  These  experiments  form  a  continuation 
of  those  given  in  Table  2,  with  hydrochloric  acid  in  place  of  quinine 
bihydrochloride.  The  action  of  hydrochloric  acid  in  causing 
lit 
