466 
Alkaloidal  Assays. 
(  Am.  Jour.  Pharm. 
I     October,  1899. 
tion  to  the  solution  of  iodine  and  separating  the  periodide  by  shak- 
ing, have  very  little  color,  or  be  almost  colorless,  then  it  is  certain 
that  the  drug  is  very  rich,  and  either  a  smaller  quantity  of  the  drug 
or  a  larger  quantity  of  the  iodine  solution  must  be  employed  in  the 
assay. 
Generally,  if  the  drug  contains  as  much  as  3  per  cent,  of  alkaloid, 
1  gramme  should  be  taken  for  the  assay ;  if  it  contains  less  than  the 
above  amount,  but  not  less  than  T2^-  of  I  per  cent,  of  alkaloid,  then  a 
quantity  between  I  and  5  grammes  should  be  taken. 
THE  IODINE  FACTORS. 
Quantity  of  Alkaloid   Quantity  of  Alkaloid  to 
The  Precipitate  Formed.  ~to  roooo  of  Iodine      i  C.c.  of  Tenth-normal 
Consumed.  Solution  of  Iodine.1 
Atropine,  CnH23N03.HI.I8  0-785  0-00361 
Morphine,  C1TH19N03.HI.I3   0-749  0*00948 
Strychnine,  C21H22N202.HI.I6  0-439  0-00556 
Brucine,  C23H26N204.HI.I6  .  .  0-518  0-00655 
Mean  of  strychnine  and  brucine  0-478  0-00605 
Emetine,2  C28H40N20O5.HI.I7  0-55  o*co6 
Hydrastine,  C21H21N06.HI.I5  0-604  0*00764 
Caffeine,  C8H10N4O2.HI.I4  0-383  0-00485 
THE  ASSAY  OF  OPIUM. 
The  Extraction  of  the  Morphine  and  its  Volumetric  Estimation  Either  by 
Standardized  Solution  of  Acid  or  by  Standardized  Solution  of  Iodine? 
For  the  use  of  hot  extraction  instead  of  cold  percolation  in  treat- 
ment of  the  opium  in  this  process,  see  the  accompanying  article, 
1  If  the  analyst  prefers  to  standardize  his  volumetric  solution  of  iodine  to  ex- 
act decinormal  strength,  or  to  adjust  the  consumption  of  iodine  to  this  strength 
by  use  of  a  correcting  factor,  then  he  will  multiply  the  cubic  centimeters  of 
iodine  solution  consumed  by  the  proper  factor  in  this  column.  (1  c.c.  deci- 
normal solution  contains  0-012653  gramme  of  iodine.)  The  more  simple  way, 
however,  is  to  register  the  actual  quantity  of  iodine  in  1  c.c.  of  the  solution,  be 
the^same  above  or  below  the  0-012653  gramme,  and  multiply  this  actual  quantity 
by  the  number  of  cubic  centimeters  used  up,  so  as  to  get  the  weight  of  iodine 
consumed.  This,  multiplied. by  a  factor  of  the  first  column  above,  gives  the 
quantity  of  alkaloid  estimated,  in  grammes. 
2  That  is,  a  provisional  representative  of  the  total  alkaloids  of  ipecacuanha. 
3  This  method  of  assay  with  the  iodometric  estimation  appeared  in  its  primary 
form,  with  the  analysis  of  morphine  tetraiodide,  etc.,  in  an  article  by  the 
present  authors,  in  June,  1898  {Pharm.  Archives,  I,  p.  121),  and  with  some 
additions  in  "Proc.  Am.  Phar.  Assoc.,"  1898,  p.  340  (also  in  /.  Am.  Chem.  Soc, 
1898,  p.  724).  The  directions  with  adaptation  to  the  alkalimetric  way  of  esti- 
mation, as  here  given,  formed  a  part  of  "The  Assay  of  Opium  :  A  Supple- 
mentary Note  "  in  the  Pharmaceutical  Review,  77,  1899,  and  to  appear  in  the 
Archiv  der  Phan?iacie. 
