5?o 
Sodium  Salicylate. 
Am  Jour  Pharrn. 
Dec,  187* 
is  as  follows  :  Take  of  pure  crystallized  salicylic  acid  (that  of  Germans 
manufacture  is  the  best  in  the  market)  1  part.  Take  of  pure  crys- 
tallized and  uneffloresced  sodium  monocarbonate  (that  obtained  by  the 
recrystallization  of  commercial  sal  soda  is  usually  sufficiently  pure) 
1*04  part.  Add  to  the  acid  in  a  glass  or  earthenware  vessel  sufficient 
water  to  form  a  paste,  and  gradually  add  the  sodium  carbonate.  The 
salt  is  readily  decomposed,  the  carbonic  anhydride  being  evolved,  and 
the  sodium  salicylate  formed  entering  into  solution  in  the  water  present. 
If  the  constituents  were  pure,  filtration  should  be  unnecessary,  but  if 
required  filter  through  paper,  or  preferably,  strain  through  fine  muslin 
into  a  water-bath  of  block  tin  or  porcelain.  Heat  until  the  dissolved 
carbonic  anhydride  is  expelled,  and  then  test  the  reaction  of  the  solu- 
tion either  with  test  paper  or  with  a  few  drops  of  test  solution.  In 
this  connection  it  may  be  well  to  state  that  the  removal  of  a  few  drops 
and  the  addition  of  the  test  liquid  is  preferable,  as  the  action  upon  test 
paper  is  rather  indistinct  unless  the  solution  be  quite  considerably  dilu- 
ted. If  the  solution  is  alkaline,  add  salicylic  acid  in  slight  excess ;  if 
any  considerable  excess  of  acid  is  present,  render  nearly  neutral  by  ad- 
dition of  sodium  carbonate.  It  is  necessary  to  be  quite  careful  in  this, 
as  any  considerable  excess  of  acid  will  render  the  salt,  to  a  slight  ex- 
tent, insoluble  in  water,  and  the  slightest  excess  of  alkali  will  invaria- 
bly render  the  salt  of  a  shade  varying  from  a  light  gray  to  a  deep  lead 
color.  Evaporate  to  dryness  upon  the  water-bath  with  constant  stir- 
ring, avoiding  more  than  a  moderate  heat,  lest  the  salt  be  partially  de- 
composed and  some  of  the  salicylic  acid  be  sublimed. 
The  resulting  salt  will  be  of  a  very  nearly  pure  white  color,  and  ex- 
hibits no  tendency  to  change  upon  exposure  to  the  air.  It  is  readily 
and  completely  soluble  in  nine-tenths  of  its  weight  of  water  at  6o°F.„ 
and  in  about  '65  of  its  weight  at  i8o°F.,  the  solution  being  of  a  light 
amber  color. 
Alcohol  of  95  per  cent,  dissolves  about  one-tenth  of  its  weight  at 
6o°F.,  and  at  I20°F.  about  one-seventh  of  its  weight  of  the  salt,  while 
glycerin  at  i8o°F.  dissolves  50  per  cent,  of  its  weight,  the  solution 
remaining  perfect  when  cooled  to  6o°F. 
This  process  differs  somewhat  from  any  heretofore  recorded  in  the 
journal,  and  while  all  of  them  may  yield  satisfactory  products,  I  con- 
sider that  this  has  several  manifest  advantages  over  any  of  them. 
Mr.  John  Williams  ("Am.  Jour.  Pharm.,"  187^  p.  546)  gives  a 
