136 
Cupreine  and  Homoquinine. 
j  Am.  Jour.  Pharm. 
\      March,  1886. 
to  remove  spirit;  the  residue  had  a  strong  alkaline  reaction  and  was 
extracted  with  ether  which  dissolved  only  a  minute  quantity  of 
cupreine.  The  remaining  alkaline  liquid  was  neutralized  with  hydro- 
chloric acid  and  mixed  with  potassium  iodide  solution  which  gave  a 
precipitate  of  methyl  cupreine  iodide.  This  compound  can  be  ob- 
tained more  readily  by  mixing  an  alcoholic  solution  of  cupreine  with 
methyl  iodide.  After  a  short  time  methyl  cupreine  iodide  separates 
from  the  solution  almost  entirely  and  can  be  obtained  pure  by  a  crys- 
tallization from  boiling  water.  It  forms  small  colorless  needles  which 
are  anhydrous,  very  sparingly  soluble  in  cold  water  or  alcohol  and 
insoluble  in  ether,  but  very  soluble  in  acids  and  alkalies.  The  iodide 
is  not  sensibly  altered  when  a  solution  in  caustic  alkali  is  boiled  for  a 
long  time,  and  on  neutralizing  the  solution  it  is  again  precipitated,  but 
of  a  slight  yellow  color.  Its  composition  is  represented  by  the  formula 
C19H22X202CH3I.  The  corresponding  chloride  was  obtained  by  di- 
gesting the  iodide  with  freshly  precipitated  silver  chloride  and  hot 
water.  On  cooling  the  solution  it  crystallized  in  small  needles,  spar- 
ingly soluble  in  cold  water,  readily  in  hot  water  with  yellow  color. 
The  solution  becomes  dark  reddish-brown  with  ferric  chloride,  with 
very  little  chlorine  and  ammonia  dark  green.  The  salt  is  readily 
soluble  in  acids  and  alkalies,  but  gives  no  fluorescence.  The  platino- 
chloride  C19H22N202.CH3,PtCl6H4-H20  is  an  orange-colored  crystal- 
line precipitate  slightly  soluble  in  water. 
The  neutral  sulphate  (C19H22X202.CH3)2S04  was  obtained  by  digest- 
ing the  iodide  with  silver  sulphate  and  hot  water.  By  evaporating 
the  yellow  solution  the  sulphate  crystallized  in  small  needles,  very 
soluble  in  cold  water,  and  giving  the  above-mentioned  reactions  with 
ferric  chloride  and  chlorine  and  ammonia. 
The  base  was  obtained  by  adding  barvta  water  to  a  hot  solution  of 
the  sulphate.  On  evaporation  the  base  remains  as  a  yellow  amorphous 
mass ;  it  is  very  bitter,  insoluble  in  ether,  very  soluble  in  water.  The 
solution  has  a  strong  alkaline  reaction;  when  mixed  with  a  small 
quantity  of  ferric  chloride  hydrated  ferric  oxide  is  at  first  precipitated 
and  re-dissolved  on  adding  more  ferric  chloride,  the  solution  becoming 
dark  reddish-brown.  The  solution  of  the  base  mixed  with  excess  of 
chlorine  becomes  of  a  fine  deep  red  color  on  the  addition  of  ammonia, 
but  with  only  a  small  quantity  of  chlorine  a  green  color  is  pro- 
duced. The  base  dissolves  in  excess  of  dilute  sulphuric  acid  with- 
out fluorescence,  but  in  alcohol  with  bluish-green  fluorescence.    It  is 
