Am.  Jour.  Pharm.  | 
Jan.  2, 1871.  j 
Sulphocarholie  Acid,  etc. 
13 
The  weight  of  the  three  dilferent  precipitates  will  also  teach  us  the 
composition  of  both  sulphocarbolic  acid  and  sulphocarbolate  of 
baryta. 
Thus,  100  grains  of  the  mixture  contained  76-35  grs.  of  sulphuric 
acid,  79  p.  c.  or  60-31  grs.  of  anhydrous  sulphuric  acid,  and  23-65 
grs.  of  carbolic  acid. 
Of  these  60-31  grs.  of  sulphuric  acid,  31*64  grs.  remained  free,  as 
shown  by  the  92  grs.  of  sulphate  of  baryta  (precipitate  6'),  formed  by 
it.  Thence,  the  balance,  28-67  grs.,  was  combined  with  23-65  grs.  of 
carbolic  acid,  forming  a  certain  amount  of  sulphocarbolic  acid,  which 
saturated  27:22  grs.  of  baryta,  as  shown  by  the  41  grs.  of  sulphate 
baryta  precipitated  by  an  excess  of  sulphuric  acid  (precipitate  a). 
We  have  then  for  the  composition  of  sulphocarbolate  of  baryta  the 
following  proportions : 
Sulphuric  acid,     ....    28-67  grs. 
Carbolic      "       .  .  .  .    23-65  " 
Baryta,    .  .  .  .  .  27-22 
Dividing  these  numbers  by  the  respective  equivalents  of  the  chemi- 
cals they  represent  we  obtain  : 
Sulphuric  acid,        .        .    7-16  ['    or,  in    ^  6  equiv. 
Carbolic      "  .        .    2-48^    round    V2  " 
Baryta,   ....    3*54  (numbers,  J  3  " 
This  does  not  evaluate  the  equivalent  or  equivalents  of  water,  but 
is  a  sure  guide  for  the  preparation  of  sulphocarbolic  acid  and  the  sul- 
phocarbolates. 
Preparation  of  Sulphocarholie  Acid. 
This  is  the  process  I  should  recommend  to  prepare  pure  sulphocar- 
bolic acid  : 
Carbolic  acid  (Calvert's  No.  1),       .  .    188  grs. 
Sulphuric  acid,  pure,  79  p.  c,         .  .    607  " 
Carbonate  baryta,   .  .  .  q.  s.,  or  636  " 
Melt  the  carbolic  acid,  add  to  it  the  sulphuric  acid  by  small  portions, 
and  let  stand  in  a  warm  place  till  all  smell  of  carbolic  acid  has  dis- 
appeared. Dilute  the  liquid  with  eight  times  its  volume  of  water,  add 
the  carbonate  baryta,  bring  to  ebullition  and  filter.  The  filtrate 
should  give  no  precipitate  with  either  sulphuric  acid  or  nitrate  baryta. 
As  sulphuric  acid  is  of  variable  strength,  and  the  quantity  of  car- 
