1 1 8  Presence  of  Tannin  in  Gentian  Root.  {Am£l.ri8P76.arm' 
Leconte  (uJour.  de  Phar.,"  xxiii) ;  in  1838  by  Dulk  (tcArch.  d.  Phar.,', 
xv)  ;  in  1847.  by  Baumert  ("Ann.  d.  Chem.  u.  Phar.,"  lxii) ;  in  1861 
by  H.  Ludwig  ("Arch.  d.  Phar./'  clvii),  and  in  1862  by  Kromayer 
(ibid.,  clx).  To  these  investigations  must  be  added  the  recent  ones  by 
Hlasiwetz  and  Habermann  ("  Buchn.  N.  Repert.,"  1874,  p.  631  ; 
"Amer.  Jour.  Phar.,"  1875,  p.  207).  It  is  true  that  many  of  these 
analyses  were  undertaken  with  the  principal  object  of  isolating  the 
bitter  principle  or  the  gentianic  (gentisic)  acid  ;  but  it  is  hardly  to  be 
supposed  that  a  principle  like  tannin,  the  presence  of  which  is  so 
readily  proven,  should  have  been  overlooked.  More  particularly  is 
this  the  case  with  the  analyses  of  Henry  and  Caventou,  Leconte  and 
Dulk,  the  two  former  of  which  were  undertaken  for  the  purpose  of 
ascertaining  all  the  constituents,  and  that  of  Dulk  verified  the  substan- 
tial correctness  of  the  results  of  the  former. 
The  results  obtained  by  these  chemists  agree  perfectly  well  with  the 
physiological  effects  observed  by  numerous  physicians,  and  which  may 
be  summed  up  with  the  words  of  Pereira  :  "  Gentian  is  very  properly 
regarded  as  a  pure  or  simple  bitter ;  that  is,  as  being  bitter,  but  without 
possessing  either  astringency  or  much  aroma."  Moreover,  none  of  the 
works  on  Materia  Medica,  in  the  English,  French  and  German  lan- 
guages, which  the  writer  had  occasion  to  consult,  mentions  tannin  or  a 
similar  compound  in  this  root. 
In  the  face  of  these  numerous  investigations,  it  must  appear  rather 
startling  to  learn  that  Mr.  E.  L.  Patch,  in  a  paper  recently  read  before 
the  Massachusetts  College  of  Pharmacy,  asserted  that  "he  found  tannin 
in  the  gentian,  contrary  to  the  usual  statement  of  works  on  Materia 
Medica"  ("Drug.  Circ,"  1876,  p.  48).  This  assertion  seems  to  be 
mainly  based  on  "  the  incompatibility  of  the  tincture  of  chloride  of 
iron  and  the  compound  tincture  of  gentian,"  although  it  is  stated  that 
Mr.  Patch  exhibited  numerous  preparations  of  gentian  in  connection 
with  his  paper.  Unfortunately,  the  gentleman  seems  to  have  over- 
looked the  fact,  that  the  tincture  mentioned  contains  also  orange  peel, 
and  that  the  white  parenchyma  of  the  latter  is  colored  of  a  deep  black 
on  the  addition  of  solution  of  any  ferric  salt,  which  coloration,  accord- 
ing to  Fliickiger  and  Hanbury  ("  Pharmacographia,"  pages  105,  113), 
is  owing,  "probably,  to  a  kind  of  tannic  matter."  It  will  be  observed 
that  the  authors  mentioned  are  very  guarded  in  their  expression,  not- 
withstanding the  ink-black  coloration  produced  by  iron  salts. 
