Am  Jour.  Pharm.  \ 
September,  189s.  J 
Alkaloidal  Periodides. 
441 
Ratio  of  alkaloid  to 
1  ofiodine. 
Total 
Iodine 
calc. 
Total 
Iodine 
found. 
Additive 
Iodine 
calc. 
Additive 
Iodine 
found 
Per  cent, 
sol.  made 
Per  cent, 
found  by 
vol.  anal. 
A  ("rnniti  f» 
C2849 
— .  
7o*/i8 
/y  4° 
yo'88 
7o*o8 
O"  ^0 
n"  A  1 
u  4/ 
80' 11 
79-6  2 
7 1 '  I S 
0-40 
0-30 
o"*6 
0-28 
Strychnine  .  .  . 
72-66 
7270 
62-28 
62.14 
I'OOO 
1-026 
0-4390 
69-21 
72-54 
62-34 
1 -6 1 2 
0  633 
Brucine  .... 
69  04 
59'32 
59-i9 
I'OOO 
0-999 
o-5i79 
79-04 
59-37 
0-5 
0-497 
Morphine     .  .  . 
64-03 
63-80 
48-02 
48  29 
051s 
0-525 
074918 
63-54 
48-44 
0-259 
0-257 
o-ioo 
o"  ro5 
Aconitine    .  .  . 
57'85 
55 '93 
49-58 
49 '03 
In  the  case  of  atropine  the  authors  obtained  two  mercuric  iodides 
respectively  C17H23N03HI.HgI2  and  (ClvH23N03HI)2HgI2.  They 
can  be  prepared  by  treating  the  periodide  with  metallic  mercury, 
and  in  other  ways  described. 
In  the  volumetric  estimations,  the  iodine  solution  is  made  of  deci- 
normal  strength,  with  sufficient  potassium  iodide  and  a  correspond- 
ing strength  of  solution  of  sodium  thiosulphate  is  used.  To  a  known 
volume,  constituting  an  excess  of  the  iodine  solution,  a  measured 
quantity  of  an  aqueous  salt  solution  of  the  alkaloid  is  added  gradually; 
the  mixture  is  shaken  until  the  liquid  becomes  clear,  when  an  aliquot 
part  of  all  is  filtered  off  and  the  excess  of  iodine  determined  by 
titrating  with  thiosulphate  to  an  end  reaction  with  starch. 
The  authors  have  elaborated  a  volumetric  method  of  opium  assay, 
upon  the  following  plan  :  The  opium  alkaloids  are  set  free  by  action 
of  ammonia  with  certain  solvents  applied  to  the  powdered  opium. 
The  free  narcotine,  paraverine,  codeine  and  thebaine  are  then  re- 
moved by  percolation  with  benzene  (bensol),  after  which  the  mor- 
phine is  wholly  taken  out  by  percolation  either  with  amyl  alcohol  or 
with  acetone.  Both  these  solvents  have  been  used.  The  percolation  is 
effected  well  by  admixture  of  dry  common  salt  with  the  opium 
powder.  The  solvent  is  evaporated  from  the  percolate  of  morphine, 
and  the  residue  taken  up  with  lime  water,  whereby  the  alkaloid  is 
purified  from  color  and  other  extraneous  matters.  The  filtered  lime 
solution  is  acidulated,  and  the  morphine  in  it  estimated  directly  as 
periodide.  One  gramme  of  opium  is  quite  sufficient,  and  two  or 
more  final  titrations  can  be  obtained  from  this  quantity. 
In  the  results  of  opium  assay  by  this  method,  repeated  operations 
give  figures  agreeing  quite  closely  with  each  other.    So  far  as  com- 
