322       RESEARCHES  ON  THE  CONSTITUTION  OF  QUININE. 
The  formation  of  this  body  may  be  exhibited  by  the  following. 
C40H24N2O4    +     C4H5I    =    C44H2()N2  04  I 
Quinine.  Iodide  of  eth}rle.  Iodide  of  ethyle-quinine. 
Iodide  of  methyle-quinine.  An  analogous  combination  may 
be  had  on  adding  iodide  of  methyle  to  an  ethereal  solution  of 
quinine,  when,  after  a  while,  crystals  are  deposited  very  similar 
to  the  former. 
The  crystals  were  dried  at  110°  C.  before  analysing  them, 
when  from  0.2412  grm.  was  obtained,  0.4792  grm.  carbonic  acid, 
0.1285  grm.  water,  from  0,3624  grm.  0.1805  iodide  of  silver, 
which  results  agree  with  the  formula  C42  H27  N2  04  I. 
Calculated.  Found. 
42  C          252       54.1  54.2 
27  H           27         5.8  5.9 
2  N           28         —  — - 
4  0  32  — 
1  I          127       27.3  26.9 
466 
C40  H24  N2  04  +  C2  H3  I  =  C42  H27  N2  04  I. 
A  watery  solution  of  iodide  of  methyle-quinine  or  ethyle-quinine 
is  not  precipitated  by  ammonia,  like  other  salts  of  quinine  f  an 
addition  of  potassa  at  first  leaves  it  clear,  but  after  a  large  quan- 
tity has  been  added,  a  turbidness  occurs,  and  a  precipitate  is 
formed  which  dissolves  in  water  more  readily  when  heated,  and, 
on  cooling,  deposits  crystals  resembling  the  original  iodides ; 
which,  indeed,  have  not  been  decomposed  by  potassa,  but  only 
precipitated,  as  they  are  insoluble  in  that  liquid.  The  separation 
of  iodine  takes  place  without  difficulty  by  oxide  of  silver,  which, 
added  to  a  solution  of  iodide  of  ethyle-quinine  in  water,  forms 
yellow  iodide  of  silver,  and  leaves  the  solution  strongly  alkaline. 
If  oxide  of  silver  is  added  until  the  formation  of  iodide  of  silver 
ceases,  and  the  filtered  solution  is  evaporated  in  vacuo  above  sul- 
phuric acid,  the  residue  is  uncrystallizable  and  becomes  hard 
and  pulverable  very  slowly.  It  is  easily  soluble  in  water  and 
alcohol ;  in  the  latter  solution  ether  occasions  a  turbidness  and 
separates  a  syrupy  stratum  which  slowly  deposits  colorless 
needles.  The  aqueous  solution  of  this  base  has  a  caustic  and 
bitter  taste,  readily  absorbs  carbonic  acid  from  the  atmosphere^ 
