Am.  Jour.  Pharm.  1 
May,  1910.  / 
Anhydrous  Sodium  Sulphite, 
217 
into  which  30  c.c.  of  strong  (93  per  cent.)  sulphuric  acid  were 
placed;  while  the  other  perforation  in  the  stopper  was  used  for 
uniting,  by  means  of  suitable  tubing,  the  inner  atmosphere  of  the 
flask  with  that  of  the  separatory  funnel;  the  arrangement,  there- 
fore, being  the  same  as  that  previously  used  10  for  the  preparation 
of  chlorinated  soda  solution.  The  delivery  tube  of  the  flask  was 
connected  with  a  small  Drechsel  gas  washing  bottle,  in  which  were 
placed  40  Gin.  of  recently  distilled  water.  The  Drechsel  bottle  was 
placed  in  a  glass  jar  containing  ice-water  and  unmelted  ice,  and 
its  outlet  tube  was  connected  with  a  piece  of  glass  tubing  which 
led  into  a  test-tube  containing  a  little  of  a  strong  solution  of  sodium 
carbonate.  After  all  the  connections  had  been  made,  the  stop-cock 
of  the  separatory  funnel  was  turned  so  as  to  let  the  sulphuric  acid 
fall  slowly  in  drops  on  the  solid  Na2SOs  in  the  flask.  Heat  was  not 
applied  at  the  beginning-  of  the  operation,  but  when  the  current  of 
S02  was  observed  to  have  weakened,  gentle  heating  was  applied  to 
the  flask,  and  the  operation  continued  until  practically  the  entire 
available  S02  had  been  evolved.  When  thus  carried  out  not  even 
the  slightest  odor  of  S02  could  be  noticed  in  the  room  in  which  this 
operation  was  performed.  The  Drechsel  and  contents  were  weighed 
before  and  after  the  passage  of  the  S02  into  it  and  the  increase 
in  weight  was  found  to  be  6.8  Gm.,  corresponding,  therefore,  to 
8.7  Gm.  of  sulphurous  acid,  H2SOs.  To  combine  this  amount 
of  H0SO3  with  Na2SO;3  so  as  to  yield  the  acid  salt, 
NaHSOo,  it  would  require  13.4  Gm.  of  pure  Na2S03,  or  13.96 
Gm.  of  a  sample  containing  96  per  cent.  Na2S03.  The  latter 
quantity  was,  therefore,  added  to  the  sulphurous  acid  solution  in 
the  Drechsel,  the  removable  upper  part  of  the  latter  was  replaced 
by  a  cork,  and  the  contents  well  shaken.  It  was  then  transferred 
to  a  beaker  of  about  250  c.c.  capacity  and  200  c.c.  of  alcohol 
added  to  it.  The  beaker  and  contents  were  then  placed  in  the  ice- 
water  bath,  the  contents  well  mixed,  and  the  whole  allowed  to 
remain  in  this  bath  for  about  15  minutes.  The  precipitate 
formed  was  filtered  off  on  a  Hirsch  funnel  with  the  aid  of  the 
vacuum  pump  until  no  more  liquid  could  be  observed  to  drain  from 
the  funnel ;  the  final  drying  being  effected  by  pressing  between 
layers  of  filter  paper.  The  weight  of  the  bisulphite  thus  obtained  in 
the  solid  state  was  found  to  be  over  11  grammes,  representing, 
"  Amer.  Jour.  Pharm.,  82,  161-166  (1910). 
