14 
Sulphocarholic  Acid,  etc. 
f  Am,  Jour.  Pharm. 
1     Jan.  2,  1871. 
bonate  of  baryta  is  intended  only  to  accurately  saturate  and  remove 
the  free  sulphuric  acid,  it  may  be  necessary  to  add  to  the  filtrate  a 
little  carbonate  baryta  or  sulphuric  acid,  till  it  answers  the  requisite 
test.  The  liquid  should  be  then  evaporated  at  a  gentle  heat,  away 
from  the  influence  of  light,  and  allowed  to  crystallize. 
Pure  sulphocarholic  acid  is  colorless,  has  no  smell,  dissolves  in 
water,  alcohol  and  ether,  in  all  proportions  ;  it  does  not  seem  to  pos- 
sess any  antiseptic  properties,  for  its  watery  solution  becomes  mouldy 
in  forty-eight  hours  when  the  weather  is  warm.  Nitric  acid,  espe- 
cially with  the  help  of  heat,  decomposes  it,  forming,  among  other  com- 
pounds, picric  and  sulphuric  acids. 
Sulijhocarholate  of  Soda. 
This  salt  may  be  prepared  by  saturating  sulphocarholic  acid  by 
carbonate  of  soda.  By  evaporation,  abundant  crystals  are  obtained 
without  difficulty. 
Sulphocarbolate  of  soda  is  inodorous,  almost  colorless ;  it  is  red- 
dened by  exposure  to  direct  sunlight.  The  shape  of  its  crystals  is 
very  much  like  that  of  sulphate  of  zinc.  It  is  neither  efflorescent 
nor  deliquescent.*  It  dissolves  readily  in  water,  less  so  in  alcohol, 
not  at  all  in  ether.  Nitrate  of  baryta  causes  no  precipitate  in  its 
solution.  Sulphocarbolate  of  soda  cannot  be  kept  in  weak  solution 
without  turning  mouldy  in  warm  weather.  It  is  decomposed  by  nitric 
acid  into  sulphate  soda,  free  sulphuric  and  picric  acids,  etc. 
Sulpliocarholate  of  Zinc 
Is  obtained  by  saturating  sulphocarholic  acid  w^ith  a  slight  excess  of 
carbonate  or  oxide  of  zinc  recently  precipitated.  It  crystallizes 
easily,  in  the  shape  of  flattened  prisms.  It  has  no  smell,  no  color,  or 
hardly  any,  and  tastes  very  much  like  sulphate  of  zinc.  It  is  soluble 
in  water  and  in  alcohol.  It  is  not  precipitated  by  salts  of  baryta. 
Direct  sunlight  aff'ects  it  much  more  than  the  corresponding  salt  of 
soda,  so  that  it  is  more  difficult  to  obtain  colorless.  It  is  decomposed 
by  nitric  acid  in  the  same  manner  as  sulphocarbolate  of  soda.  Its 
solutions  turn  mouldy  in  warm  weather,  unless  they  are  concentrated. 
The  other  sulphocarbolates  may  be  prepared  in  the  same  manner, 
should  any  be  required. 
Though  the  above  experiments  show  that  pure  sulphocarbolates 
*  It  tastes  like  sulphate  of  soda ;  slightly  bitter  and  salty,  but  not  acrid. 
