324         ON  THE  MANUFACTURE  OF  TARTARIC  ACID,  ETC. 
that  described  for  decomposing  citrate  of  potash  with  salts  of 
lime,  and  with  the  same  amount  of  sulphate  of  lime  as  there 
employed.  The  citrate  of  lime  produced  is  separated,  and  the 
sulphate  of  soda  existing  in  solution  may  be  obtained  by  evapo- 
ration and  crystallization. 
The  salts  of  baryta,  strontia,  and  lime,  which  are  to  be  em- 
ployed in  decomposing  citrate  of  potash,  may  be  employed  to 
decompose  citrate  of  soda,  and  may  be  employed  in  a  similar 
manner  and  in  the  same  proportions  as  when  employed  to  de- 
compose solutions  of  citrate  of  potash.  The  citrate  of  lime  and 
citrate  of  baryta  or  strontia  resulting,  may  be  decomposed  by 
means  of  sulphuric  acid  in  the  same  manner  as  citrate  of  lime 
is  now  decomposed  in  the  manufacture  of  citric  acid,  and  citric 
acid  be  therefrom  obtained.  The  sulphide  of  potassium  and  the 
sulphide  of  sodium  employed,  may  be  obtained  by  heating  a  mix- 
ture of  either  sulphate  of  potash  or  sulphate  of  soda  with  small 
coal,  coal-dust,  or  powdered  charcoal,  in  a  reverberatory  furnace, 
or  otherwise,  until  the  whole  or  the  greater  proportion  of  the 
sulphate  of  potash  or  sulphate  of  soda  is  reduced  and  converted 
into  sulphide  of  potassium  and  sulphide  of  sodium.  These  sul- 
phides being  soluble  in  water,  they  may  either  be  employed  in 
solution,  or  the  fused  mass  may  be  used  direct,  or  these  sulphides 
may  be  obtained  from  other  sources  London  Pharmaceutical 
Journal,  Jan-  1854. 
MANUFACTURE  OF  TARTARIC  ACID,  PURIFIED  BITARTRATE  OF 
POTASH,  BIOXALATE  OF  POTASH,  TARTRATE  OF  SODA  AND 
POTASH,  AND  CARBONATES  OF  SODA  AND  POTASH  * 
In  the  ordinary  mode  of  obtaining  tartaric  acid,  the  excess  of 
acid,  existing  in  crude  bitartrate  of  potash  (argols  and  tartar) 
is  neutralized  with  chalk,  with  the  formation  of  insoluble  tartrate 
of  lime  and  soluble  tartrate  of  potash.  The  latter  salt  is  then 
decomposed  by  the  agency  of  sulphate  of  lime,  and  a  further 
portion  of  tartrate  of  lime  is  thus  formed.  In  this  case,  as  in 
that  of  the  citrate  of  lime  before  mentioned,  much  of  the  or- 
ganic coloring  matters  present  are  precipitated  with  the  tartrate 
By  the  Editor  of  the  London  Pharmaceutical  Journal. 
