Am.  Jour.  Pharm.  \ 
September,  lt>97.  J 
Gelsemic  Acid. 
441 
(5)  When  silver  nitrate  is  added  to  an  aqueous  solution  of  G.  A., 
at  first  a  yellow  precipitate  is  produced,  which  quickly  changes  to 
black.  Solutions  of  auric  and  platinic  chlorides  are  reduced  at 
once. 
(6)  Fehling's  solution,  or  a  concentrated  solution  of  copper  sul- 
phate, gives  a  brownish-red  precipitate  of  suboxide  on  standing,  or 
immediately  on  heating. 
(7)  The  addition  of  freshly-prepared  chlorine  water  to  an  aqueous 
solution  of  G.  A.  produces  a  red  coloration  which  disappears  on 
warming. 
(8)  The  addition  of  Lugol's  solution  produces  a  brown  precipi- 
tate, which  consists  of  a  mixture  of  free  iodine  and  gelsemic  acid. 
Analytical. — Dr.  Robbins  assumes  gelsemic  acid  to  be  a  gluco- 
side,  after  boiling  its  aqueous  solution  with  diluted  sulphuric  acid, 
and  heating  with  Fehling's  solution.  In  the  above  cited  reactions 
we  find  that  gelsemic  acid  is  a  strong  reducing  agent,  reacting  even 
in  cold  solution,  so  this  test  is  indeed,  under  the  circumstances, 
fallacious. 
To  ascertain  whether  this  principle  is  a  glucoside  or  not,  samples 
were  boiled  for  twelve  hours  with  diluted,  also  concentrated,  hydro- 
chloric acid,  also  with  diluted  sulphuric  acid,  finally ;  a  sample  was 
heated  in  a  sealed  tube  with  5  per  cent,  alcoholic  hydrochloric  acid 
at  I  io°  C.  All  gave  negative  results,  the  gelsemic  acid  remaining 
unchanged,  and  the  solution  failing  to  give  any  reaction  for  sugar 
with  phenylhydrazine.  Other  sugar  tests  cannot  be  applied,  because 
of  the  above-mentioned  reducing  properties  of  this  principle. 
Robbins  as  well  as  Wormley  calls  attention  to  the  acid  properties 
of  G.  A.  The  former  states  that  the  salts,  with  exception  of  the  alka- 
lies, are  insoluble  in  water,  while  the  latter  are  crystalline.  Robbins 
assumes  that  the  precipitate  obtained  by  adding  a  salt  of  a  metal  to 
solution  of  G.  A.  was  a  compound  of  the  latter  with  a  metallic  base. 
I  have  already  stated  that  these  precipitates  consist  of  a  mixture  of 
basic  hydroxides  and  free  acid. 
I  endeavored  to  obtain  salts  of  G.  A.  with  the  alkalies  by 
cautiously  neutralizing  aqueous  and  alcoholic  solutions  of  this  princi- 
ple with  alkali  carbonates  and  hydrates.  The  resulting  solutions  were 
concentrated  at  the  lowest  possible  temperature,  and  set  aside  for 
some  weeks,  with  the  result  that  nothing  more  than  amorphous 
crusts  could  be  obtained. 
