460 
PURIFICATION  OF  VEGETABLE  JUICES. 
of  seed,  which  have  furnished  17  kilogrammes  of  oil,  in  value 
27  fr.  20  c.  There  remain  then  42  fr.  30  c.  for  the  500  gram- 
mes of  opium. — Echo  Medical  de  Neuchdtel  and  Journal  de 
Pharmacie  d'Anvers. 
PURIFICATION  OF  TOGETABLE  JUICES. 
Presented  to  the  French  Academy  of  Sciences,  January  14,  1861. 
By  M.  Emim  Rousseau. 
In  the  saccharine  juices  of  vegetables,  that  of  the  best  not 
being  taken  as  an  example,  there  are  found  two  kinds  of  organic 
substances,  which  must  interfere  with  the  extraction  of  the  sugar. 
The  first  belongs  to  the  group  of  albuminoid  and  caseous  sub- 
stances. It  undergoes  all  the  modifications  which  reagents  pro- 
duce on  solutions  of  albumen  and  casein.  The  salts  of  lime  and 
lime  itself  coagulate  it ;  but  the  latter,  whether  by  its  proper 
alkaline  action  it  dissolves  a  portion  of  the  vegetable  substance 
and  retains  it  in  combination  as  was  lately  shown  by  Fremy,  or 
because  it  sets  free  some  potassa  or  soda,  causes  the  saccharine 
juices  treated  by  it  to  remain  always  alkaline,  after  the  action 
of  carbonic  acid.  These  two  efi'ects  are  often  united,  and  an 
ulterior  alteration  of  the  syrup  takes  place,  which  is  recognized 
in  the  commonest  kinds  of  sugar. 
The  second  substance  is  colorless  ordinarily,  as  long  as  it  re- 
mains in  the  cellules  of  the  vegetable,  but  very  greedy  of  oxy- 
gen, coloring  rapidly  under  the  influence  of  air,  suffering  mod- 
ifications rapidly  from  the  action  of  oxidating  agents,  so  that 
it  is  entirely  converted  into  the  well  known  substance  which  is 
produced,  when  vegetable  juices  are  evaporated  or  entirely  de- 
stroyed. This  substance,  when  deprived  of  albuminoid  matter, 
reduces,  with  the  aid  of  heat,  the  salts  of  silver,  protoxide  of 
mercury,  &c.  Through  the  action  of  this  latter  body  the  solu- 
tion takes  the  same  color  which  the  juice  acquires  by  long  ex- 
posure to  the  air. 
The  facts  being  established,  the  problem,  how  to  simplify  the 
fabrication  of  sugar  may  be  stated  thus  :  wanted  (1)  a  substance 
of  slight  solubility,  capable  of  coagulating  all  the  albuminoid 
substances,  without  any  injurious  action  either  upon  the  sugar 
or  upon  health,  capable  of  ready  withdrawal  from  the  juice  in 
