266 
Geranium  Maculatam. 
Am.  Jour.  Pharm . 
June,  1S91. 
Where  collections  were  made  at  the  same  season  and  under 
similar  conditions  in  different  years  an  average  of  the  results  was 
taken.  In  1 891  the  plant  bloomed  earlier  than  it  did  in  1890,  which 
will  account  for  the  statement  of  blooming  in  both  April  and  May. 
It  will  be  evident  from  an  examination  of  the  above  figures  that  in 
the  spring,  just  before  blooming,  is  the  best  time  for  collecting  the 
drug.  It  will  also  appear  that  in  this  plant  the  tannin  is  a 
storage  material  used  in  assisting  the  plant  to  bloom. 
Every  one  of  the  fourteen  lots  gathered  was  tested  for  gallic  acid 
by  agitating  the  decoction  with  ether,  allowing  the  separated  ether 
to  evaporate,  and  testing  the  residue. 
Negative  results  were  gotten  in  nearly  every  case,  and  where  they 
were  not,  the  evidence  was  only  that  of  mere  traces.  Gallic  acid 
does  not  exist  in  the  plant,  but  is  easily  found  in  the  rhizome  after 
drying,  resulting  from  the  easily  decomposable  tannin.  Direct 
extraction  of  the  fresh  rhizome  also  failed  to  show  the  presence  of 
gallic  acid. 
EXTRACTION    OF  THE  TANNIN. 
To  obtain  this  principle,  a  quantity  of  the  dried  and  finely  ground 
drug  was  percolated  with  ether,  specific  gravity,  0-750,  the  solvent 
distilled,  the  extracted  matter  treated  with  water,  filtered  and  the 
tannin  precipitated  from  the  filtrate  with  lead  acetate.  This  preci- 
pitate was  rapidly  washed,  decomposed  by  hydrogen  sulphide  in  the 
presence  of  water  and  concentrated  by  distillation  under  reduced 
pressure.  The  concentrated  solution  was  agitated  with  stronger 
ether,  which  was  subsequently  separated  and  the  distillation  of  the 
aqueous  solution  continued,  under  the  above  conditions,  to  dryness, 
a  red-brown,  somewhat  porous  mass  being  obtained.  The  ether 
removed  considerable  gallic  acid. 
This  tannin  was  not  completely  soluble  in  cold,  but  readily  soluble 
in  hot  water.  Weak  solutions  remained  permanent  for  a  reasonable 
time,  but  a  one  per  cent,  solution  rapidly  deposited  a  red-brown 
precipitate  which  may  be  called  geranium  red.  After  this  deposi- 
tion the  solution  was  red  in  color  and  reacted  as  follows  with  a 
number  of  tannin  reagents  : 
Cobalt  acetate,   purplish  brown  ppt. 
Manganese  acetate,   light 
"Cranium  acetate,  '.   dark-red  color. 
Potassium  dichromate,   brown  precipitate. 
