58 
OLEUM  ^THEREUM. 
The  character  of  the  chemical  changes  which  occur,  are  diffi- 
cult to  determine,  and  have  not  been  studied  with  sufficient  experi- 
ment and  accuracy  to  warrant  definite  and  precise  statements 
concerning  them.  Therefore  what  now  follows  upon  this  point  is 
to  be  regarded  as  the  result  of  a  judgment,  based  upon  observa- 
tions in  practice,  rather  than  as  accurate  results  obtained  by 
direct  experiment. 
The  writer  does  not  agree  with  those  authorities  who  regard 
heavy  oil  of  wine  as  a  sulphate,  or  double  sulphate,  but  rather 
with  those  who  regard  it  as  a  sulphovinate  of  a  hydrocarbon 
base,  and  for  this  prominent  reason,  that  when  pure  and  recent  it 
fails  in  giving  any  of  the  characteristic  reactions  of  sulphuric 
acid  or  sulphates. 
If  it  be,  as  the  writer  believes  it  is,  a  sulphovinate  of  one  or 
more  hydrocarbon  bases,  the  chemical  changes  which  occur  by 
keeping  are  probably,  first,  that  a  portion  of  the  salt  is  decom- 
posed by  a  simple  separation  into  its  proximate  elements,  just  as 
chemically  pure  chloroform  separates  by  keeping,  and  that  after 
the  separation  a  small  proportion  of  the  sulphovinic  acid  is  re- 
duced to  sulphuric  acid,  and  that  this  reproduced  sulphuric  acid 
reacts  upon  the  more  loosely  combined  hydrocarbons  by  separa- 
ting and  combining  with  the  elements  of  water  and  setting  the 
carbon  free. 
The  upper  stratum  is  therefore  regarded  as  mainly  composed  of 
the  hydrocarbon  base  with  a  little  ether.  The  lower  stratum  as 
being  mainly  sulphovinic  acid,  or  a  lower  sulphovinate  of  the 
hydrocarbon  base,  holding  in  solution  a  considerable  proportion 
of  the  original  heavy  oil  of  wine,  rendered  acid  by  a  small  portion 
of  reproduced  sulphuric  acid,  and  colored  by  free  carbon.  By 
supplying  the  matrix  to  the  mixture  of  these  two  strata,  namely, 
ether,  they  are  made  to  recombine  in  the  original  form  and  propor- 
tion with  the  exception  of  the  small  portion  which  was  decomposed 
into  sulphuric  acid  water  and  free  carbon,  and  the  chain  or  cir- 
cuit of  the  original  compound  is  re-formed,  and  rendered  per- 
manent. If  these  views  be  true,  the  analogy  with  chloroform  is 
very  close  and  perfect  in  this  respect,  since,  as  the  writer  has  else- 
where shown,  decomposed  chloroform  may  be  regenerated  and 
recombined  by  the  similar  use  of  its  matrix,  namely,  alcohol. 
The  writer  sees  no  reason  to  believe  that  in  the  changes  by 
