Aoctobe?' 1915™'}     Examination  of  Opium  Alkaloids.  453 
for  medicinal  purposes.  Although  the  tests  are  tentative  in  nature,  it 
was  thought  worth  while  to  publish  them  in  the  hope  that  they  might 
prove  useful  to  analysts,  and  also,  possibly,  to  manufacturers  who 
may  wish  to  prepare  standards  for  the  substances  in  question. 
In  preparing  these  tentative  monographs  an  endeavor  was  made 
to  select  and  arrange  the  qualitative  tests  so  that  they  should  be  as 
distinctive  as  possible  for  the  particular  alkaloid  sought.  For 
example,  narcotine,  papaverine,  and  thebaine  are  each  precipitated 
by  potassium  ferricyanide  solution,  but  at  widely  different  dilutions. 
According  to  Plugge,17  narcotine  and  thebaine  are  not  precipitated 
by  this  reagent  from  dilutions  above  0.25  per  cent.,  while  papa- 
verine may  still  be  precipitated  from  dilutions  of  0.025  per  cent,  if 
the  solution  be  allowed  to  stand.  Narceine  may  be  precipitated  from 
its  salts  by  potassium  ferricyanide  solution  as  free  alkaloid.  Mor- 
phine and  codeine  are  not  precipitated  as  ferricyanides  even  from 
highly-concentrated  solutions.  Consequently,  by  taking  care  that 
the  alkaloidal  solution  be  less  than  0.25  per  cent,  in  strength,  papa- 
verine alone  of  the  six  more  important  opium  alkaloids  is  precipi- 
tated by  potassium  ferricyanide  as  the  alkaloidal  ferricyanide.  Again, 
narcotine  and  papaverine  are  the  only  alkaloids  of  the  group  which 
are  precipitated  in  the  free  state  by  sodium  acetate  solution. 
Monograph  I. 
NARCEINE  (C23H2708N  .  3H20). 
Narceine.  occurs  in  fine,  white,  silky  needles  or  in  white  prisms 
which  may  be  partially  effloresced  to  a  grayish-white  powder ;  odor- 
less and  having  a  slightly  bitter  taste,  with  a  styptic  after-taste. 
Slightly  soluble  in  water;  readily  soluble  in  hot  water;  slightly 
soluble  in  alcohol ;  readily  soluble  in  hot  alcohol ;  insoluble  in  ether ; 
insoluble  in  chloroform,  petroleum  ether,  or  benzene;  soluble  in  a 
warm  mixture  of  equal  parts  of  chloroform  and  isobutyl  alcohol; 
somewhat  soluble  in  ammonia  water  and  in  diluted  potassium  hy- 
droxide solution. 
At  1000  C.  narceine  loses  its  water  of  hydration  (10.8  per  cent.). 
If  exposed  to  the  air  the  anhydrous  alkaloid  absorbs  water  equiv1 
alent  to  one  molecule  of  water  of  hydration.  The  water  of  hydra- 
tion in  commercial  narceine  is  variable,  the  quantity  depending  some- 
what on  the  method  of  crystallization. 
11  Arch.  Pharm.,  225,  809  et  seq.  (1887). 
