XtSeSI  Gelsemic  Acid.  439 
GELSEMIC  ACID.1 
By  VirgiIv  Cobi,e;ntz. 
This  principle  was  first  isolated  by  Professor  Maisch,  in  1869, 
later  named  and  fully  described  by  Professor  Wormley  in  1870. 
The  latter  author  restricted  himself  to  the  application  of  various 
color  tests  and  the  deportment  of  this  substance  to  different  reagents, 
with  the  view  of  its  identification  from  the  standpoint  of  a  toxi- 
cologist. 
Dr.  Chas.  Robbins,  in  his  work  "Ueber  die  wesentlichen  bestand- 
theile  von  Gelsemium  sempervirens"  (1876),  describes  this  principle 
as  occurring  in  needle-like  crystals,  which  separate  in  stellate 
groups,  possessing  acid  characters  and  forming  salts  with  alkalies, 
all  of  these  salts  being  insoluble  in  water  except  those  of  the  alka- 
lies which  are  readily  soluble  and  crystalline.  As  regards  solubili- 
ties, the  same  author  claims  that  gelsemic  acid  is  readily  soluble  in 
chloroform  and  ether,  and  soluble  1  part  in  1000  of  water.  A 
number  of  color  reactions  given  by  Wormley  were  reviewed  by  Rob- 
bins.    These  will  be  taken  up  later  with  criticisms  and  comments* 
The  material  for  the  following  investigations  was  supplied  by 
Professor  J.  U.  Lloyd,  who  assured  me  of  its  purity  and  genuineness. 
The  crystals  were  white,  when  viewed  in  mass,  of  a  slight  yellowish 
cast ;  they  were  of  the  hexagonal  system  and  varied  in  length  from  5 
to  10  mm.2 
The  melting  point  of  gelsemic  acid,  which,  to  my  knowledge,  has 
not  been  published,  at  least  not  by  the  above-named  investigators, 
is  2060  C.  (corrected). 
When  heated  between  no°  and  1 1 5 0  C.  for  five  hours  in  a  tube, 
through  which  a  currrent  of  dry  carbonic  anhydride  was  passed,  no 
appreciable  loss  in  weight  occurred ;  in  the  upper  portion  of  the 
tube  a  slight  sublimate  was  noticeable.  This  may  account  for  Dr. 
Robbins'  two  molecules  of  crystal  water.  However,  the  solvent 
employed  in  crystallizing  may  account  for  differences.  When 
heated  in  open  air  gelsemic  acid  takes  on  a  deep  lemon-yellow 
color. 
xRead  at  the  meeting  of  the  American  Pharmaceutical  Association,  1897. 
2  Made  from  Gelsemium  sempervirens  by  means  of  neutral  solvents  only, 
no  acids  or  alkalies  being  employed.  Purified  by  repeated  crystallizations 
from  alcohol. — J.  U.  I*. 
