REMARKS  ON  POLYGALIC  ACID. 
149 
REMARKS  ON  POLYGALIC  ACID. 
By  "William  Procter,  Jr. 
Among  the  questions  proposed  last  year  for  investigation,  the 
following  was  accepted  by  me  : — 
"  What  is  the  most  eligible  process  for  obtaining  Polygalic 
acid  from  Senega  ?  In  what  proportion  does  it  exist  in  that 
root  ?  And  what  are  the  forms  for  prescribing  it  as  substitutes 
for  the  preparations  of  seneka  ? 
Seneka  snake  root,  as  one  of  the  most  efficient  American  con- 
tributions to  the  Materia  Medica,  early  attracted  the  attention 
of  European  pharmaceutists  and  chemists,  and  at  least  half  a 
dozen  analyses  of  it  had  been  published  more  than  twenty  years 
ago,  when  it  was  very  fully  investigated  by  Quevenne,  (Jour,  de 
Pharm.,  1836,  449)  in  his  inaugural  essay  sustained  at  the 
School  of  Pharmacy,  at  Paris. 
According  to  this  analysis  the  constituents  of  seneka  are  as 
follows,  viz.  : — 
INORGANIC. 
Carbonate, Phosphate  and  Sulphate 
of  Potassa, 
Chloride  of  Potassium, 
Carbonate,  Sulphate, and  Phosphate 
of  Lime, 
Alumina,  Magnesia,   Silica,  and 
Iron. 
Polygalic  acid, 
Virgineic  acid, 
Pectic  acid, 
Tannic  acid, 
Bitter  yellow  coloring  matter, 
Gum,  Albumen,  &c, 
Cerin,  and  fixed  oil. 
Polygalic  acid,  so  called  by  Quevenne,  was  previously  made 
known  in  a  less  pure  state,  as  senegin,  by  Gehlin.  It  is  the  ac- 
tive constituent  of  the  root,  although  some  influence  may  be  due 
to  the  virgineic  acid  and  coloring  principle.  It  may  also  be 
noticed  that  both  Dulong  and  Foenuille  found  malic  acid  in  this 
root,  united  with  lime  and  potassa. 
It  may  not  be  out  cf  place  to  state  the  characteristics  of  this 
substance,  as  it  is  certainly  deserving  of  a  better  destiny  than 
has  thus  far  been  accorded  to  it.  Polygalic  acid  is  a  white 
amorphous  powder,  without  any  tendency  to  crystallize,  and  is 
unalterable  in  the  air.  It  is  inodorous  when  pure,  but  is  apt  to 
retain  traces  of  virgineic  acid.  Its  taste,  at  first  but  slight, 
soon  becomes  pungent  and  acrid,  and  produces  a  painful  con- 
