Amju°nue!"i89h8arm"}    Atropine  Per  iodides  and  Iodomer  curates,  297 
plete  series  from  the  tri-iodide  to  the  enneaiodide.  And  in  fact  in 
the  course  of  our  work  we  once  obtained  this  heptaiodide.  But  our 
efforts  to  determine  the  exact  conditions  necessary  for  the  formation 
of  this  body  have  so  far  not  been  successful. 
The  easiest  way  to  obtain  the  periodides  of  atropine  is  to  use 
chloroform  as  a  solvent.  On  adding  twenty  grammes  atropine  to  a 
warm  solution  of  thirty  grammes  iodine  in  chloroform  (500  c.c.)  the 
enneaiodide  crystallizes  out  very  soon  in  the  shape  of  small,  shining, 
dark-green  crystals.  If  these  be  removed  by  filtration,  the  mother- 
liquor  will  give  several  successive  crops  of  the  dark-blue  pentaiodide 
and  at  last  a  crop  of  the  brownish-red  tri-iodide. 
II.  ATROPINE  MERCURIC  IODIDES. 
The  periodides  of  atropine,  like  those  of  many  other  alkaloids, 
easily  give  double  salts  with  mercuric  iodide,  obtained  on  shaking 
the  alcoholic  solution  of  the  periodide  with  mercury  and  gently 
warming  the  mixture.  This  double  iodide  of  atropine  and  mercury 
can  also  be  made  by  mixing  theoretical  quantities  of  atropine  and 
iodine,  adding  a  little  alcohol  and  an  excess  of  mercury,  slightly 
warming,  and  shaking  till  the  color  of  iodine  disappears.  If  the 
higher  periodides  of  atropine  be  used  in  the  preparation  of  this 
double  iodide  of  atropine  and  mercury,  there  is  always  separation  of 
mercurous  iodide  ;  but,  if  theoretical  quantities  of  atropine  and  iodide 
are  used,  there  is  no  separation  of  mercurous  iodide.  The  formula 
of  this  double  iodide  of  mercury  and  atropine,  as  shown  by  our 
analysis,  seems  to  be  C17H23N03.HI.HgI2.  It  resembles  in  composi- 
tion several  other  double  iodides  of  alkaloids  and  mercury  obtained 
by  Groves1  by  a  different  method.  But  besides  this  double  iodide 
we  also  obtained  another  having  the  composition  (Atrop.  HI)2.HgI2. 
It  was  made  by  treating  a  solution  of  the  Atrop. HI. HgT2  in  diluted 
alcohol  with  an  excess  of  potassium  iodide.  From  the  liquor 
obtained  by  shaking  an  alcoholic  solution  of  atropine  and  iodine 
with  mercury  the  monoatropine  hydriodide  mercuric  iodide  crystal- 
lizes out  in  shining  yellow  crystals,  melting  at  890  to  900  C,  diffi- 
cultly soluble  in  ether  or  chloroform,  partly  soluble  in  hot  water. 
The  analysis  for  mercury  and  for  iodine  in  these  bodies  can  be 
made  in  different  ways,  but  the  best  results  are  obtained  by  a  modi- 
fication of  the  method  of  Risse.'2    The  mercury  and  the  iodine  are 
1  Quart.  J.  of  Chem.  Soc,  11,  97. 
2  Ann.  Chem.  (Liebig),  107,  223. 
