DIFFERENCES  OF  ACTION  BETWEEN  POTASSA  AND  SODA.  551 
reduced  by  this  operation,  the  residue  must  be  moistened  with 
nitric  acid  and  again  calcined.  The  dry  mass  is  then  dissolved 
in  cold  water,  the  solution  strongly  acidulated  with  nitric  acid, 
and  water  added  until  ten  parts  of  the  solution  contain  one  of 
the  salt.  The  liquid,  which  is  of  a  golden  yellow  color,  must 
be  preserved  from  ammoniacal  fumes. 
It  precipitates  the  solutions  of  all  the  alkaloids,  with  the  ex- 
ception of  urea,  when  a  mere  trace  only  is  present.  The  pre- 
cipitates are  yellow,  generally  flocculent,  insoluble  in  water,  alco- 
hol, ether,  and  the  dilute  mineral  acids,  with  the  exception  of 
phosphoric  acid.  Nitric,  acetic,  and  oxalic  acids,  concentrated 
and  boiling,  dissolve  them.  These  compounds  are  decomposed 
by  the  alkalies,  certain  metallic  oxides,  and  the  alkaline  salts, 
which  separate  the  alkaloid. 
To  give  an  idea  of  the  sensibility  of  this  new  reagent,  it  may 
be  stated  that  the  0.000071  gramme  of  strychnia  gives  an  ap- 
preciable precipitate  with  one  cubic  centimetre  of  the  solution 
of  phospho-molybdic  acid. — London  Pharm.  Journ.  Sept.  1858. 
OBSERVATIONS  ON  CERTAIN  DIFFERENCES  OF  ACTION,  BE- 
TWEEN  POTASSA  AND  SODA,  WITH  REGARD  TO  VARIOUS 
ORGANIC  MATTERS,  IN  THE  PRODUCTION  OF  OXALATES  AND 
CYANIDES. 
By  M.  L.  Possoz. 
In  endeavoring  to  apply  economically,  in  an  industrial  point  of 
view,  the  scientific  data,  published  by  Gay  Lussac  [Annales  de 
Chimie  et  de  Physique,  1829),  on  the  production  of  oxalic  acid,  by 
the  action  of  the  hydrates  of  potassa  and  soda  on  various  organic 
matters,  I  observed  that  in  this  reaction  soda  was  far  from  acting 
exactly  like  potassa ;  and  having  frequently  observed  analogous 
facts  in  other  circumstances,  I  thought  that  it  would  be  useful  to  call 
the  attention  of  chemists  to  this  point,  for  we  are  too  often  led  to 
regard  the  action  of  these  two  bases  as  identical.  Thus,  as  re- 
gards the  oxalates,  not  only  does  hydrate  of  soda  produce,  in  all 
cases,  much  less  oxalic  acid  for  a  given  weight  of  organic  matter, 
but  also  with  certain  substances  it  produces  none  at  all,  and  with 
others  gives  only  traces ;  however,  when  it  is  united  with  hydrate 
