696 
Determination  of  Morphine. 
Am.  Jour.  Pharm. 
Oct.,  1918. 
sodium  hydroxide  solution  was  added  to  the  tetrathionate  thus 
formed.  This  was  then  titrated  with  sulphuric  acid,  the  indicator 
being  phenolphthalein. 
B.  A  titration  was  made  as  in  the  previous  case,  but  the  tetra- 
thionate present  was  that  yielded  by  100  Cc.  of  -3%  iodine  solution. 
C.  A  measured  volume  of  the  standard  alkali  was  added  to  50 
Cc.  of  the  sodium  thiosulphate  solution  used  above.  It  was  then 
titrated  as  in  A  and  B. 
D.  A  blank  experiment  was  made  in  which  the  standard  alkali 
was  titrated  against  -fg  acid  without  any  previous  admixture.  Titra- 
tion results : 
A.  B.  C.  D. 
NaOH  solution  used    25.00  Cc.    25.00  Cc.    25.00  Cc.    25.00  Cc. 
rNo  H2S04  required  to  neutralize  . .  10.65  Cc.     9.90  Cc.    12.00  Cc.    12.00  Cc. 
The  neutrality  of  the  iodine  solution  used  in  the  above  experiments 
was  shown  by  taking  50  Cc,  adding  just  enough  sodium  thiosul- 
phate to  decolorize  it,  and  testing  the  resulting  solution  with  lac- 
moid,  methyl  orange  and  cochineal.  With  all  these  it  gave  a  neutral 
reaction. 
The  Extraction  of  Morphine  by  a  Mixture  of  Chloroform  and 
Alcohol  (2:1).  Experiment  5. — Crystallized  morphine  (0.3000 
Gm.)  was  dissolved  in  dilute  sulphuric  acid.  The  solution  was 
transferred  to  a  separating  funnel,  and  enough  ammonium  hydroxide 
was  added  to  make  it  strongly  alkaline,  care  being  taken  that  the 
total  volume  did  not  exceed  25  Cc. 
The  solution  was  well  shaken  for  3  minutes  with  25  Cc.  of  a 
mixture  of  chloroform  and  alcohol  (2  volumes  of  the  former  to  1 
volume  of  the  latter).  The  lower  layer  was  separated  and  the  ex- 
traction repeated  in  exactly  the  same  way.  In  all,  four  extractions 
were  thus  made. 
The  united  extracts  were  distilled  on  a  water  bath,  the  residue 
being  then  dissolved  in  standard  sulphuric  acid,  the  excess  of  which 
was  later  titrated  with  standard  sodium  hydroxide  solution  and  lac- 
moid  indicator. 
[The  standard  acid  used  in  this  and  most  succeeding  experiments 
was  slightly  less  than  x\,  being  so  adjusted  that  1  Cc.  =  0.0300  Gm. 
crystallized  morphine.] 
