GROWTH  AND  PREPARATION  OF  RHUBARB  IN  CHINA.  157 
on  Mongolia,  north  of  the  lake  Koko-nor,  and  in  the  Nan-chan 
mountains,  and  everywhere  among  the  high  mountains  of  the 
province  of  Sz-chuen  (or  Si-chwan),  which  lies  to  the  east  of 
Thibet,  and  3 — 400  miles  north-east  of  the  northern  extremity  of 
Birmah. 
Description  of  the  Plant. — The  root  resembles  that  of  the 
Chinese  potato,  or  white  yam  (Dioscorea  Batatas).  It  is  from 
one  to  two  feet  long,  and  thick  enough  to  be  used  as  a  pillow.  It 
is  covered  with  a  black  skin,  is  soft  and  moist,  and  contains  a 
yellowish  sap.  The  plant  puts  forth  its  leaves  in  the  first  or 
second  month.  The  unexpanded  leaves  of  the  Sz-chuen  plant  in 
the  second  month,  are  of  a  deep  yellowish  color ;  those  of  the 
Shen-si  plant,  in  the  first  month,  are  green,  as  large  as  a  fan, 
and  resemble  those  of  the  Pima  (Ricinus  communis.  Linn.) 
Kung  describes  the  rhubarb  leaf  as  coarse,  long,  and  thick.  In 
Sz-chuen,  the  stem  is  more  than  3  feet  high  in  the  second  month. 
According  to  Kung,  who  does  not  mention  the  locality,  the  stem 
attains  the  height  of  6  or  7  feet,  and  is  red,  crisp,  sour,  and 
eatable  in  its  raw  state.  In  the  third  or  fourth  month  it  opens 
its  yellow  flowers,  which  are  succeeded  in  the  fifth  month  by  a 
black  seed  (nut).  The  root,  leaf  and  stalk  of  rhubarb,  according 
to  Kung,  resemble  those  of  the  Yang-ti  plant.  This  writer  says 
that  the  root  is  red,  but,  in  other  respects,  his  description  of  it 
accords  with  that  of  the  other  writers. 
Preparation  and  Drying  of  the  Hoot. — The  root  is  taken  up 
in  the  second  or  eighth  month,  and  the  black  skin  which  covers 
it  is  removed.  It  is  then  cut  in  slices,  either  longitudinally,  as 
in  Sz-chuen,  or  transversely,  as  in  Shen-si  and  elsewhere,  and 
dried  in  the  shade  with  or  without  artificial  heat.  The  following 
mode  of  drying  is  said  to  be  the  best : — a  stone  is  heated,  and  the 
roots,  cut  in  traverse  slices  about  an  inch  thick,  are  placed  upon 
it.  By  this  means  the  pieces  are  partly  dried.  A  hole  is  then 
made  in  each,  and  the  pieces  are  strung  on  a  cord,  and  suspended 
in  the  shade  until  they  are  perfectly  dry  and  fit  for  the  market. 
Quality. — The  rhubarb  (hwang)  which  grows  in  Shen-si,  Kan- 
suh,  and  in  the  west  of  Sz-chuen,  is  all  of  good  quality.  That 
which  grows  in  Shan-si,  Chil-li,  and  other  places  to  the  north  of 
these,  is  smaller,  and  not  equal  in  strength  to  that  of  Sz-chuen. 
