248     ON  THE  ADULTERATION  OF  PRECIPITATED  SULPHUR. 
rectified  spirit,  hence  the  production  of  a  small  quantity  of  sul- 
phovinic  acid  might  be  considered  possible.  To  ascertain 
whether  or  not  this  were  so,  a  portion  of  the  diluted  spirit  was 
treated  with  carbonate  of  barium ;  the  sulphate  of  barium  separ- 
ated by  filtration,  washed  with  acid  and  water,  dried  and  weighed. 
The  filtrate,  which  would  contain  sulphovinate  of  barium,  if  sul- 
phovinic  acid  had  originally  been  present,  was  evaporated  to  a 
small  bulk  over  a  water-bath.  The  weight  of  the  sulphate  of 
barium  corresponded  with  that  of  the  sulphuric  acid,  whence  it 
was  obtained ;  indeed,  it  was  apparently  somewhat  greater — a 
result  due,  probably,  to  loss  of  alcohol  during  manipulation,  and 
a  corresponding  increase  of  strength  of  the  diluted  acid.  The 
filtrate  from  the  sulphate  of  barium  finally  dried  up  without 
giving  any  sulphovinate  of  barium.  These  experiments  were 
repeated,  after  the  mixture  of  sulphuric  acid  and  spirit  had  been 
set  aside  for  fourteen  days,  with  the  same  result ;  indicating  that 
sulphovinic  acid  is  not  formed  after  a  time.  They  were  also 
repeated  after  due  maceration  with  the  aromatics,  but,  again,  no 
sulphovinic  acid  was  obtained.  We  are,  therefore,  now  in  a  po- 
sition to  state  that  aromatic  sulphuric  acid,  when  made  accord- 
ing to  the  Pharmacopoeia,  contains  no  sulphovinic  acid. — London 
Pharm.  Journ.,  Feb.,  1869. 
NOTE    ON    THE    ADULTKRATION    OF  PRECIPITATED 
SULPHUR. 
By  Pkofessor  Attfield. 
Why  is  precipitated  sulphur  still  usually  adulterated  to  a 
scandalous  extent  with  what  may  be  termed  plaster  of  Paris, — 
hydrous  sulphate  of  calcium  (CaS04,2H20)  ?  Nearly  every 
book  on  chemistry  and  materia  medica  states  that  instead  of 
being  made  by  mixing  hydrochloric  acid  and  polysulphide  of 
calcium,  it  is  often  prepared  by  the  reaction  of  sulphuric  acid 
and  the  sulphur  salt,  the  result  being  precipitated  sulphur  (iden- 
tical, so  far,  with  the  officinal  article — Sulphur prcecipitatum  B. 
P.),  but  mixed  with  more  than  an  equal  weight  of  the  calcareous 
mineral  compound,  which  when  well  dried  constitutes  plaster  of 
Paris.    Every  chemist  and  druggist  therefore  knows,  or  ought 
