Am.  Jour.  Pharm 
April,  1884. 
Pipitzahoic  Acid  and  Species  of  Perezia. 
191 
towards  the  apex.  The  akenes  are  whitish,  glandular,  puberulent, 
cylindrical,  and  have  a  pappus  of  copious  hairs. 
The  root  of  a  slightly  "bitter  and  astringent  taste,  imparts  to  strong 
alcohol  a  dingy  yellow  tint,  which  by  the  addition  of  a  weak  solution 
of  a  caustic  alkali  deepens  to  a  clear  deep  yellow  color.  If  a  very 
dilute  solution  of  sodic  or  potassic  hydrate  is  carefully  added,  a  faint 
and  evanescent  tint  of  impure  purple  color  is  perceptible,  indicating 
the  presence  of  small  quantities  of  pipitzahoic  acid  combined  with 
another  substance.  As  would  be  expected  by  the  deepening  of  the 
color,  in  consequence  of  the  addition  of  an  alkali  to  the  tincture,  this 
substance  proved  to  be  a  tannic  acid,  ferric  chloride  producing  an  abun- 
dant precipitate  of  dark  green  color,  which  disappeared  by  the  addition  of 
oxalic  acid.  To  obtain  the  pipitzahoic  acid  pure,  the  alcoholic  tincture 
of  the  root  was  treated  with  boiling  water,  and  the  very  minute  quantity 
of  a  golden  yellow  crystalline  precipitate  washed  by  decantation. 
Examined  under  the  microscope  it  was  seen  to  form  stellate  groups 
of  acicular  or  dagger-shaped  golden  yellow  crystals  characteristic  to 
this  compound,  which  by  the  addition  of  a  drop  of  diluted  solution  of  sodic 
hydrate  are  dissolved  with  the  production  of  a  beautiful  deep  violet  color. 
Incomplete  as  the  chemical  investigation  of*  the  few  decigrams  of  the 
root  of  this  plant  at  command  must  appear,  its  results  show  that  as  a 
source  of  pipitzahoic  acid,  it  is  of  but  little  value,  which  in  reference  to  the 
therapeutical  virtues  claimed  for  this  substance  as  a  mild  purgative,  is 
further  impaired  by  the  largely  predominating  quantities  of  tannic 
acid  with  which  it  is  associated.  Of  greater  interest,  in  that  respect, 
containing  considerable  quantities  of  pipitzahoic  acid  in  an  almost  pure 
state,  was  found  the  following  species : 
Crystals  of  pipitzahoic  acid,  magn.  160  diam. 
Prepared  by  precipitating  the        By  evaporating  the  alco- 
alcoholic  solution  with  water. 
hoiic  tincture  of  the  root. 
