ON  RHCSADINA. 
123 
ate  concentration  dissolve  it  at  once,  with  a  purple  color.  This 
solution  becomes  colorless  by  alkalies,  but  purple  again  on  the 
addition  of  acids.  One  part  of  the  alkaloid,  yielding  only  about 
5  per  cent,  coloring  matter,  produces,  with  10,000  parts  water, 
a  purple,  with  20,000,  an  intense  rose,  and  with  800,000,  a  per- 
ceptible red  color,  equal  to  one  part  of  the  coloring  matter  in 
sixteen  millions  parts  of  water. 
By  this  delicate  reaction,  rhoeadina  can  be  detected  in  all 
parts  of  Papaver  Rhoeas,  in  the  ripe  capsules  of  Papaver  som- 
niferum,  and  in  opium.  The  aqueous  infusion  of  opium  is  pre- 
cipitated by  carbonate  of  soda  or  lime,  the  filtrate  treated  with 
ether,  and  the  ether  agitated  with  water  acidulated  with  muriatic 
acid.  This  solution  acquires  the  color,  particularly  on  heating. 
A  portion  of  the  rhoeadina  remains  with  the  precipitate,  and 
may  be  detected  in  the  same  manner.  Merck's  porphyroxyn  con- 
tains less  than  one  part  of  this  alkaloid. 
Concentrated  sulphuric  acid  dissolves  rhoeadina  with  olive 
green,  nitric  acid,  with  yellow  color. 
The  colorless  solution  in  muriatic  acid  is  precipitated  by  tan- 
nin, corrosive  sublimate,  iodohydrargyrate  of  potassium,  ter- 
chloride  of  gold,  and  bichloride  of  platinum. 
The  purple  solution  of  rhoeadina  in  acids  is  rendered  colorless 
by  repeated  treatment  with  animal  charcoal,  and  contains  now 
another  alkaloid,-  rhoeagenina,  which  is  precipitated  by  ammonia, 
and  purified  from  hot  alcohol.  It  occurs  in  small  white  prisms, 
sparingly  soluble  in  ether,  alcohol,  water  and  ammonia,  readily  solu- 
ble in  acids  without  coloration,  except  nitric  acid,  which  decom- 
poses it,  producing  a  yellow  color.  It  is  tasteless,  but  the  salts 
are  bitter.  It  is  fusible,  but  not  sublimable,  and  is  a  strong  base 
of  the  composition  C42H21$012. 
The  author  describes  the  sulphate  and  several  other  salts,  all 
of  which  are  uncrystallizable.  He  then  suggests  the  relation  of 
rhoeadina  with  sanguinarina,  from  which  it  differs  by  lactic  acid 
C42H21N012  +  2HO=C36HirN08+G6H606;  the  formation  of  a  red 
coloring  alkaloid,  and,  as  obtained  by  J.  and  H.  Smith,  the  pro- 
duction of  lactic  acid  from  opium,  under  certain  circumstances, 
seem  to  favor  this  relation.  It  also  differs  from  Merck's  papa- 
verina  only  by  the  elements  of  carbonic  acid  (C.12II21N012  = 
