Am.  Joub.  Pharm,  1 
May  1,1871.  J 
Orah- Orchard  Salt. 
211 
phosphate  of  ammonia,  from  an  ammoniacal  solution  ;  the  phosphate 
of  ammonia  and  magnesia  thrown  down  was  filtered  off,  washed  with 
dilute  ammonia  water,  dried  and  ignited  ;  the  pyrophosphate  of  mag- 
nesia, thus  obtained,  weighed  -8354  gramme,  equal  to  15-052  per 
cent,  of  magnesia.    Two  grammes  were  dissolved  in  water,  and  pre- 
cipitated by  acetate  of  lead,  by  which  the  sulphuric  acid  was  removed, 
and  the  bases  converted  into  acetates.    The  filtrate  was  evaporated 
and  ignited,  the  mixture  of  magnesia,  oxide  of  lead  and  carbonate  of 
lime  lixiviated  with  boiling  water ;  the  filtrate  was  evaporated  with 
bichloride  of  platinum  (after  acidulation  witli  chlorhydric  acid).  The 
clilorplatinates  of  potassium  and  sodium  were  separated  by  alcohol ; 
the  chlorplatinate  of  potassium  was  decomposed  by  sulphuric  acid  ; 
the  mixture  with  a  little  oxalate  of  ammonia  was  heated  to  redness, 
to  reduce  the  platinum,  which  being  washed  and  weighed,  equaled 
•0423  gramme,  equal  to  1-012  per  cent,  of  potassa.    Two  hundred 
grammes  were  dissolved  in  water  and  filtered  from  the  insoluble  resi- 
due.   This  was  examined,  qualitatively,  and  found  to  contain,  princi- 
pally, carbonates  of  lime  and  magnesia,  silicic  acid,  both  soluble  and 
insoluble  forms,  some  sesquioxide  of  iron,  alumina,  oxide  of  man- 
ganese and  fluoride  of  calcium.    A  slight  excess  of  acetate  of  lead 
was  added,  to  precipitate  the  suliphuric  acid,  and  convert  the  bases 
into  acetates  ;  after  filtration,  these  were  evaporated,  decomposed  by 
heat,  and  lixiviated  by  boiling  water.    The  filtrate  was  precipitated 
with  sulphhydric  acid,  the  sulphide  of  lead  separated  by  filtration,  and 
the  liquid  acidulated  with  chlorhydric  acid,  was  evaporated  till  chlo- 
ride of  sodium  began  to  separate ;  then  chloride  of  platinum  was 
added,  to  separate  the  chlorplatinates  of  potassium,  rubidium  and 
caesium  (should  the  latter  be  present).     The  mixture  was  then  evapo- 
rated to  dryness  over  a  water-bath ;  the  dry  mass  tr.eated  with  dilute 
alcohol,  to  remove  the  chloride  of  sodium,  then  washed  with  stronger 
alcohol.    I  obtained  about  8  grammes  of  chlorplatinate  of  potassium, 
which  was  boiled  with  160  cubic  centimetres  of  water,  filtered,  and 
the  insoluble  residue  ignited,  the  mass  treated  as  al3ove  described,  and 
the  resulting  mixed  sulphates  were  tested  with  the  spectroscope,  by 
which  rubidium  was  very  distinctly  recognized.   The  filtrate  from  the 
chlorplatinates  was  boiled,  to  drive  off  the  alcohol ;  the  platinum  pre- 
cipitated by  sulphhydric  acid,  and  the  chlorides  evaporated  to  dryness, 
they  were  powdered,  boiled  with  absolute  alcohol,  and  filtered  and 
washed  with  alcohol ;  this  filtrate  was  evaporated  to  dryness,  the  dry 
