508 
GLEANINGS  FROM  THE  FRENCH  JOURNALS. 
test-tube  ;  afterwards  carry  it  slowly  to  ebullition,  allow  the 
excess  of  oxide  to  deposit,  and  decant  the  clear  supernatant 
liquid.  Evaporate  this  solution  to  a  syrupy  consistence  ;  if  the 
acid  is  citric,  the  liquid  is  limpid  and  of  a  beautiful  red  ;  if,  to 
to  the  contrary,  there  is  tartaric  acid  present,  the  liquid  be- 
comes cloudy  and  deposits  a  pulverulent  combination  of  tartaric 
acid  and  sesquioxide  of  iron. 
This  reaction  is  sensible  in  detecting  1  per  cent,  of  tartaric 
acid  Zeitschrift  f  ur  Chem.  and  Pharm.  and  Journ.  de  Pharm. 
Beet-root  Salts,  and  their  use  in  Saltpetre  manufacture. — M. 
H.  Schwartz  (Polytech.  Centralblatt)  says  that  the  vinasse  or 
liquid  left  in  the  still  when  fermented  beet-juice  is  distilled  for 
alcohol,  when  evaporated  to  dryness,  calcined  to  remove  organic 
matter,  and  lixiviated,  yields,  to  water,  the  following  salts  :  car- 
bonate of  potassa,  carbonate  of  soda,  chloride  of  potassium,  sul- 
phate of  potassa,  and  small  quantities  of  ferrocyanurets,  for- 
miates,  and  sulphocyanurets.  By  the  evaporation  of  this  solu- 
tion the  sulphate  of  potassa  precipitates  first,  and  the  chloride 
of  potassium  crystallizes  during  the  cooling  of  the  liquor,  ac- 
companied by  the  larger  portion  of  the  ferrocyanuret.  The 
mother  water  evaporated  to  dryness  produces  a  grey  mass, 
which  by  expression  becomes  red,  from  the  oxidation  of  iron 
present.  By  lixiviation  and  filtration,  the  carbonated  alkaline 
salts  are  obtained  white  by  evaporation.  This  impure  carbon- 
ate of  potassa  may  be  employed  in  the  preparation  of  saltpetre 
by  double  decomposition  with  nitrate  of  soda  and  crystallization. 
— Journ.  de  Chem.  Med. 
Action  of  water  on  the  mineral  salts  of  vegetable  substances. — 
M.  A.  Terreil,  in  a  note  to  the  Academy  of  Sciences,  says 
that  the  phosphate  of  lime  and  magnesia  exist  in  plants  in  a  pe- 
culiar condition,  that  they  are  soluble  in  water  through  the 
agency  of  organic  matter,  and  can  then  be  moved  easily  in  the 
circulation  of  the  vegetable  and  deposited  in  the  parts  where 
they  are  required  in  its  development. 
From  this  fact  the  author  infers 
1st.  That  the  products  of  macerating,  infusing  and  decocting 
medicinal  plants,  owe  perhaps  a  part  of  their  action  on  the  econ- 
omy to  the  phosphoric  acid  and  phosphates  that  they  contain. 
