Am,  Jour.  Pharm.  ) 
Nov.  1, 1871.  i 
Polygonum  Hydropiper, 
491 
moved  by  means  of  basic  acetate  of  lead,  was  treated  with  sulphuric 
acid,  in  order  to  remove  the  excess  of  lead,  and  then  rendered  alka- 
line by  means  of  caustic  potash  and  treated  with  ether. 
The  ether  was  separated  and  allowed  to  evaporate  spontaneously. 
The  mass  thus  left  was  perfectly  white,  neutral  to  test-paper,  and  had  a 
bitter  taste,  was  soluble  in  alcohol,  ether,  and  the  mineral  acids;  its 
solution  in  acids  was  not  precipitated  by  ammonia,  caustic  potash,  or 
sodic  carbonate,  nor  was  I  able  to  obtain  any  crystals.  From  this 
I  concluded  that  it  possessed  no  basic  properties. 
Experiment  ^d. — One  pound  of  fluid  extract  (480  grs,,  to  the  fluid- 
ounce)  was  treated  with  hydrochloric  acid,  about  five  drops  of  the 
acid  to  each  fluid-ounce  of  the  liquids,  and  then  treated  with  ether. 
The  ether  separated  and  treated  with  basic  acetate  of  lead,  the  pre- 
cipitate produced  was  collected  on  a  filter  and  washed  with  distilled 
water,  the  precipitated  magma  was  suspended  in  distilled  w^ater  and 
treated  with  sulphuretted  hydrogen. 
The  mixture  of  sulphide  of  lead  and  organic  principle  was  again 
treated  with  ether,  the  ether  separated  from  the  sulphide  of  lead, 
evaporated  and  the  acid  crystallized. 
The  crystals  produced  resembled  those  as  prepared  in  experiment 
No.  1. 
Ohemical  properties  of  Polygonic  Acid.  Polygenic  acid,  as  prepared 
in  experiments  1  and  3,  has  a  green  color,  acrid,  and  bitter  taste. 
It  has  strong  acid  properties,  completely  neutralizing  bases,  and 
uniting  with  them  to  form  salts. 
Aqua  ammoniee,  caustic  potash  and  sodic  carbonate,  added  to  the 
crystals  or  a  solution  of  the  crystals,  produced  an  intense  yellow 
color,  and  the  crystals  were  dissolved.  Nitric  and  hydrochloric  acids 
added  to  crystals  or  solution  of  the  acid  produced  a  yellow  color. 
Sulphuric  acid  added  to  the  crystals  or  a  solution  of  polygenic  acid, 
produced  a  dark  red  color,  which  gradually  became  black.  Basic 
acetate  of  lead  added  to  a  solution  of  the  acid  or  its  salts,  produced  a 
yellow  precipitate,  soluble  in  the  mineral  acids.  Nitrate  of  suboxide  of 
mercury  produced  a  yellowish  white  precipitate,  soluble  in  the  mineral 
acids.  Mercuric  chloride  produced  a  green  precipitate,  soluble  in  the 
mineral  acids.  Cyanide  of  potassium  produced  a  yellow  color.  Ferric 
chloride  produced  a  slight  dark  color.  Cupric  sulphate  produced  a 
slight  green  color.  Baric  chloride,  chloride  of  gold,  nitrate  of  silver 
and  chloride  of  platinum  produced  no  change. 
