258 
Gelsemine  and  Crystalline  Salts. 
(  Am.  Jour.  Pharm. 
I      May,  1883. 
their  removal  the  gelsemine  swells  into  vesicles  which,  on  cooling,  can 
be  easily  powdered. 
Proj^erties  of  Gelsemine. — It  is  a  brittle  transparent  solid,  crystalliz- 
ing with  difficulty  from  alcohol.  Boiling  w^ater  sparingly  dissolves  it, 
the  solution  on  cooling  becoming  faintly  turbid  from  separation  of 
gelsemine.  It  softens  at  38°  C.  and  becomes  fused  at  45°  C.  Heated 
on  platinum  it  ignites,  burning  with  an  orange-yellow  flame  and  leav- 
ing no  trace  of  residue.  Solutions  of  its  salts  have  a  distinctly,  but  not 
a  powerfully  bitter  taste,  and  give  with  potash  or  ammonia  white  pre- 
cipitates soluble  in  excess.  If  the  solution  containing  excess  of  ammo- 
nia be  exposed  to  the  air,  as  the  ammonia  is  eliminated  the  gelsemine 
separates  in  granular  crystals.  The  pure  base  gives  no  color  reaction 
with  strong  nitric  acid,  and  the  mixture  is  scarcely  changed  in  color  by 
heating.  Strong  sulphuric  acid  has  no  apparent  reaction  upon  it ;  but 
if  to  the  mixture  a  little  manganic  oxide  be  added,  and  rubbed  with  a 
glass  rod,  a  deep  crimson  red  is  obtained,  passing  to  green.  This  reac- 
tion is  exceedingly  delicate,  and  can  be  easily  shown  by  dissolving  1 
milligramme  of  pure  gelsemine  in  10,000  milligrammes  of  strong  sul- 
phuric acid,  then  adding  a  few  milligrammes  of  manganic  oxide.  It 
can  be  even  demonstrated  with  a  solution  of  1  in  100,000.  If  the  pre- 
ceding reaction  is  performed  upon  the  pure  alkaloid,  the  color  is  suf- 
ficiently intense  to  cause  it  to  be  mistaken  for  strychnia  ;  but  if  a  par- 
allel experiment  be  carried  on  with  strychnia  the  two  alkaloids  cannot 
be  mistaken,  for  the  strychnia  gives  an  intense  purple,  passing  to  red. 
Picric  acid  gives  a  yellow  crystalline  precipitate ;  gold  chloride,  a  yel- 
low amorphous  precipitate,  soluble  in  boiling  water,  separating  on 
cooling,  partly  in  crystals.  Platinic  chloride  gives  a  yellow  precipitate, 
soluble  on  boiling. 
The  following  salts  were  prepared  and  obtained  in  crystals.  Hydro- 
chloride, hydrobromide,  sulphate  and  nitrate.  The  hydrochloride  is  a 
moderately  soluble  salt,  separating  from  water  as  an  apparently  amor- 
phous powder,  consisting  really  of  small  granular  crystals.  It  is  spar- 
ingly soluble  in  cold,  more  soluble  in  hot  alcohol ;  from  the  latter  it 
separates  slowly  in  prismatic  crystals.  The  hydrobromide  crystallizes 
more  readily  from  water  and  alcohol  than  the  hydrochloride,  forming 
prisms.  The  sulphate  and  nitrate  very  freely  soluble  in  water  and 
alcohol,  and  crystallized  indifferently  on  spontaneous  evaporation. 
Since  the  alkaloid  I  obtained  diflPered  in  important  respects  from  that 
experimented  upon  by  others,  and  was  evidently  in  a  higher  state  of 
