500  Formation  of  Oxalic  Acid  in  Vegetation.  {Am,octu,riSarm' 
nor  previously  mentioned  •  it  crystallizes  in  clusters  of  miscropic 
prisms  having  a  satin-like  lustre,  it  melts  at  73*8°,  and  resolidifies  at 
60*2°.  It  is  insoluble  in  cold,  but  somewhat  soluble  in  boiling  water, 
it  is  nearly  insoluble  in  cold,  but  readily  soluble  in  boiling  ether  and 
in  alcohol.  Qualitative  examination  indicates  that  the  compound 
belongs  to  the  fatty  acid  series. 
The  author  also  found  about  0*6  per  cent,  of  succinic  acid  in  bella- 
donna extract  prepared  from  the  herbaceous  part  of  the  plant. — Jour. 
Chem.  Sog.j  1886,  p.  255.    Archiv  d.  Phar.  [3]  xxiii. 
FORMATION  OF  OXALIC  ACID  IX  VEGETATION. 
By  Berthelot  and  Andre. 
The  plants  selected  and  examined  at  various  stages  of  their  growth 
were  Rumex  Acetosa,  Amarantus  caudatus,  Chenopodium  Quinoa, 
and  Mesembrianihemumcrystallinum.  The  juice  of  the  first  is  always 
acid,  that  of  the  second  and  third  neutral  or  feebly  acid,  whilst  that  of 
the  last  is  neutral  in  the  early  stages  of  growth,  but  becomes  acid  as 
the  plant  develops.  The  plants  also  differ  very  considerably  in 
the  ratio  between  the  soluble  and  insoluble  oxalates  which  they  con- 
tain. 
Rumex  Acetosa. — The  seed  or  dried  fruit  contains  0*05  percent,  of 
oxalic  acid.  In  the  early  stage  of  growth  (June  8th)  the  root  con- 
tains 13'9  per  cent,  of  oxalic  acid,  5*1  per  cent,  being  soluble  and  the 
remainder  insoluble.  The  proportion  of  ash  is  20  7  per  cent,  and 
some  of  the  acid  is  in  the  free  state.  When  the  plant  is  in  active 
vegetation  (June  26th),  the  absolute  quantity  of  oxalic  acid  has  in- 
creased, but  the  relative  proportion  has  diminished  owing  to  the 
development  of  ligneous  tissue  and  albuminoids.  The  total  propor- 
tion is  about  10  per  cent.,  and  it  is  especially  abundant  in  the  leaves 
and  limbs,  and  least  abundant  in  the  root,  in  which  it  is  almost  en- 
tirely insoluble  owing  to  the  proximity  of  the  calcium  compounds  in 
the  soil.  In  the  limbs,  about  one-half  is  in  the  insoluble  condition. 
The  actual  acidity  is  below  the  total  oxalic  acid  in  the  limbs,  but  is 
higher  in  the  roots  and  petioles,  and  hence  the  latter  contain  some 
acid  other  than  oxalic  acid.  The  limbs  contain  soluble  oxalate  and 
soluble  calcium  salts  in  almost  equivalent  quantities,  but  these  must 
either  circulate  in  different  vessels  or  exist  in  the  form  of  ethereal 
