•I 
:252  CuRivation  of  Bhuharb  in  Frcmce.  {^"'£y\slT'''' 
CULTIYATIOX  OF  RHUBARB  IN  FRANCE. 
The  cultivation  of  Rheum  undulatum  and  R.  rhaponticum  has  for 
some  time  past  been  carried  on  profitably  at  Clamart,  near  Paris,  and 
the  products  of  both  plants,  as  so  cultivated,  are  confounded  in  com- 
merce under  the  name  of  French  rhubarb.  Recently,  M.  Gallais  has 
been  making  some  experiments  in  the  cultivation  of  Rheum  officinale 
at  Ruffec,  in  the  Charente  department,  and  he  has  communicated  his 
manner  of  proceeding  and  results  to  the  Paris  Societe  d'Acclimata- 
tion.^ 
In  the  selecting  of  a  suitable  spot  for  the  experiment,  M.  Gallais 
-i?tates  that  he  was  guided  by  the  following  considerations :  The  Rheum 
officinale  grows  in  Asia,  between  the  30th  and  39th  parallels  of  lati- 
tude, at  an  elevation  of  4,000  feet  above  the  sea  level.  The  isother- 
mal line  of  12*9°  of  temperature  passes  by  Pekin,  of  which  the  lati- 
tude is  39°  54'  13''  N.,  and  above  Milan  rises  to  latitude  45°  54', 
running  to  the  west  of  Europe.  By  taking  this  isothermal  line  and 
.adding  half  a  degree  of  temperature  for  each  degree  of  latitude  towards 
:the  south,  and  deducting  one  degree  of  temperature  for  each  172  meters 
■of  elevation  above  the  level  of  the  sea,  he  arrived  at  the  conclusion 
that  in  the  natural  habitat  of  the  plant  the  average  climatic  tempera- 
ture was  19°  in  summer  and  zero  in  winter.  Ruifec,  the  place  where 
M.  Gallais'  experiment  has  been  carried  on,  is  situated  in  latitude 
46°  11"  N.,  longitude  2°  8'  17",  has  an  average  temperature  of  17 °C. 
in  summer  and  1'2°C.  in  winter,  and  is  at  an  elevation  of  96  meters 
above  the  sea  level. 
According  to  the  analyses  of  Fremy  and  Pelouze,  the  rhubarb  plant 
is  rather  rich  in  potash  and  sulphuric  acid,  less  so  in  silica,  more  or 
less  rich  in  lime,  and  rich  in  phosphoric  acid.  The  soil  at  Ruffec  is 
calcareous,  sandy  and  very  nitrogenous,  being  composed  partly  of 
sands  proceeding  from  old  degradations.  These  sands  contain  a  con* 
;siderable  abundance  of  silicious  and  aluminous  matters.  The  soil  is 
very  permeable,  requiring  during  the  summer  months  about  5  cubic 
meters  of  water  per  acre. 
M.  Gallais  commenced  operations  with  a  plant  obtained  from  Dr. 
Giraudeau,  which,  in  its  turn,  was  derived  from  the  original  plant 
grown  in  the  Botanical  garden  of  the  Paris  Medical  School,  from  which 
^"Bulletin"  [3],  vol.  vii,  p.  667. 
