i6o 
Root  of  Polygonum  Cuspidatum. 
/ Am.  Jour.  Pharm. 
1       March,  1896. 
and  well  known  before  the  date  of  the  patent,  and  the  proper  pro- 
portions of  the  materials  required  for  the  reaction  were  easily  ob- 
tainable by  calculation,  and  this  knowledge  also  antedated  the 
patent.  The  patent  then  simply  covers  a  specially  devised  and  de- 
scribed apparatus  and  management  which  the  writer  does  not  use, 
and  does  not  want  to  use,  even  if  they  were  not  patented,  but  much 
prefers  his  old  form  of  apparatus  and  management  described  in 
1857,  and  used  for  many  years  in  making  alcohol-chloroform  ;  and 
the  successful  use  of  this  apparatus  and  management  for  acetone- 
chloroform  is  simply  in  accordance  with  the  statement  of  Liebig,  in 
1832,  that  acetone  could  be  successfully  used  under  the  same  condi- 
tions as  alcohol. 
SOME  CONSTITUENTS  OF  THE  ROOT  OF  POLYGONUM 
CUSPIDATUM.1 
By  A.  G.  Perkin,  F.R.S.E. 
Among  the  different  varieties  of  the  species  of  Polygonum,  that 
best  known  is  perhaps  the  P.  tinctorium,  the  leaves  of  which  are 
used  as  a  source  of  indigo  in  China,  Japan,  and  some  parts  of  Russia. 
Of  others,  the  P.  aviculare  and  barbatum  yield  a  blue  color,  proba- 
bly indigo,  and  the  P.  hydropiper  and  tortosum  are  said  to  contain  a 
yellow  coloring  matter;  moreover,  the  roots  of  some  of  these  varie- 
ties possess  medicinal  value. 
The  P.  cuspidatum,  which  is  common  in  parts  of  India,  China  and 
Japan,  has  evidently  attracted  but  little  attention,  the  only  reference 
found  bearing  on  its  properties  being  the  following,  contained  in  a 
paper  (Journal  Royal  China  Branch  of  Royal  Asiatic  Society,  22, 
New  Series,  No.  5,  1887),  by  A.  Henry,  M.A.,  L.R.C.P.,  entitled 
"  Chinese  Names  of  Plants,"  "  Kan-yen,  wu-tzu,  name  at  Patung  for 
the  root  of  P.  cuspidatum,  which  is  said  to  be  used  for  dyeing  yel- 
low." 
The  roots,  which  somewhat  resemble  those  of  madder  and 
morinda,  vary  in  diameter  from  j£  inch  to  1  inch  when  fresh,  and 
consist  of  a  thick,  succulent  bark,  internally  of  an  orange-red  color, 
and  a  central  light  yellow  woody  portion  ;  the  former,  on  drying, 
shrivels  considerably  and  becomes  lighter  in  tint. 
1  Abstracted  by  J.  C.  Peacock  from  the  Journal  of  the  Chemical  Society,  De- 
cember, 1895. 
