424     AN  ALKALOID  FROM  SEEDS  OF  KICINUS  COMMUNIS. 
Preparation  of  ricinine — Crushed  castor-oil  seeds  are  ex- 
hausted by  successive  quantities  of  boiling  water,  and  the 
matters  soluble  in  water  separated  from  the  oil  and  other  in- 
soluble material  by  filtration  through  wet  calico.  The  filtered 
liquid  thus  obtained  is  then  evaporated  to  dryness  over  a  water- 
bath,  and  the  extract  produced  is  treated  with  boiling  alcohol 
•so  long  as  it  exerts  any  solvent  power.  The  alcoholic  solutions 
are  allowed  to  cool,  when  a  small  amount  of  a  resinoid  body 
precipitates.  This  is  separated  by  filtration,  and  the  filtered 
liquid  is  concentrated  to  a  small  bulk  and  allowed  to  stand  all 
night.  The  next  morning  a  mass  of  almost  white  crystals  are 
found  to  have  deposited  from  the  alcoholic  solution.  These 
crystals  are  the  new  alkaloid,  ricinine.  It  may  be  obtained 
perfectly  pure  by  recrystallization  out  of  alcohol  and  decolorizing 
by  animal  charcoal. 
Properties  of  ricinine. — Ricinine  crystallizes  in  rectangular 
prisms  and  tables.  When  placed  on  the  tongue,  it  slowly 
manifests  a  feebly  bitter  taste,  resembling  somewhat  that  of 
bitter  almonds.  Cautiously  treated  on  a  microscope  slide,  rici- 
nine melts  and  forms  a  perfectly  colorless  and  mobile  fluid, 
which  on  cooling  solidifies  into  a  whorl  of  acicular  crystals. 
Heated  between  two  watch-glasses,  a  sublimate  is  obtained, 
which  appears  to  be  unaltered  ricinine.  Strongly  heated  on 
platinum  foil,  ricinine  first  melts  and  subsequently  burns  with 
a  highly  luminous  and  fuliginous  flame. 
The  best  solvents  for  ricinine  are  water  and  alcohol ;  benzol 
and  ether  dissolve  but  a  small  quantity  of  the  alkaloid.  Heated 
with  solid  hydrate  of  potash  it  evolves  ammonia,  thus  demon- 
strating the  presence  of  nitrogen. 
Concentrated  sulphuric  acid  dissolves  the  alkaloid  without 
coloring  it,  and  the  addition  of  bichromate  of  potash  simply 
causes  the  development  of  a  green  color. 
Iodic  acid  is  not  deoxidized  by  ricinine,  even  when  these 
substances  are  warmed  together. 
Concentrated  nitric  acid  dissolves  ricinine  without  evolving 
red  vapors,  although  heat  be  applied.  On  evaporating  the 
solution  thus  produced  to  a  small  volume  and  allowing  it  to 
cool,  groups  of  transparent  and  colorless  acicular  crystals 
develope.  These  crystals  are  rendered  opaque  by  the  addition 
of  water. 
