502 
Acidime trie  Estimation  of  Alkaloids.  { 
Am.  Jour.  Pharm. 
October.  189  j. 
mentation,  it  was  found  that  Weinig's  method  gave  the  most  satis- 
factory results.  The  following  are  the  data  obtained  from  an 
approximately  normal  sulphuric  acid  solution  with  the  above 
methods  : 
Methods. 
Sodium  Carbonate. 
.  f  Brazil  wood  .  .         .  . 
2  j  Hsematoxylin  
j  Cochineal  
.«  j  Litmus  
"3  j  Methyl  orange  
n  [  Phenolphthalein  .  .  .  . 
Weinig's  method  .... 
Barium  sulphate  method 
Number  of  c.c.  of 
Acid  Solution 
required  per  io 
c.c.  of  Normal 
Sodium  Carbo- 
nate. 
Grammes  of  S03 
in  io  c.c.  of  the 
Acid  Solution. 
0-4211 
0*4192 
0'42II 
0*4211 
0*4211 
0*4216 
0*4247 
0*4200 
Due  precaution  was  taken  to  boil  the  solution  thoroughly  with 
the  indicators  requiring  it.  With  solutions  of  the  above  strength  it 
was  impossible  to  detect  any  difference  in  the  sensitiveness  of  most 
of  the  indicators. 
With  the  normal  sulphuric  acid  solution  a  normal  solution  of 
pure  potassium  hydroxide  was  standardized.  From  the  normal 
sulphuric  acid  solution  and  normal  alkaline  solution  there  were  pre- 
pared, respectively,  a  decinormal  acid  solution  and  a  centinormal 
alkaline  solution.  The  two  solutions  thus  prepared  were  carefully 
titrated  against  each  other,  employing  the  above  indicators  with  the 
following  results  : 
Indicators. 
Number  of  c.c. 
of  Normal 
S  ulphur  i  c 
Acid. 
Number   of  c.c.  of  N-100 
KOH  required  per  10  c.c. 
of  N-10  H2SO,. 
La  Wall.  Kebler. 
Phenolphthalein  .... 
10 
101*80 
102  *oo 
10 
99'56 
IOO'OO 
io~  ' 
100*58 
99  *So 
Haematoxylin   
10 
99*76 
ioo*oo 
10 
99"97 
99*60 
10 
92*67 
93-53 
