■4AprT'iPiH873M*}     Ofoate  of  Mercury  and  Morphia.  159 
The  red  oxide  of  mercury  was  triturated  with  the  nitric  acid  until 
dissolved,  and  the  resulting  solution  of  nitrate  of  mercury  diluted  with 
half  a  fluid  ounce  of  water. 
The  caustic  potassa  was  dissolved  in  the  diluted  alcohol,  contained 
in  a  dish  capable  of  holding  a  quart,  and  to  this  solution  the  oleic  acid 
was  added,  which  at  once  combined  with  the  potassa,  forming  a  clear 
solution  of  oleate  of  potassium. 
The  solution  of  nitrate  of  mercury  was  now  poured  gradually  into 
the  solution  of  oleate  of  potassium,  the  mixture  being  stirred  briskly 
with  a  glass  rod,  and  the  precipitation  of  the  oleate  of  mercury  of  the 
consistence  and  color  of  firm  white  butter  was  the  result.  On  apply- 
ing the  iodide  of  potassium  test  to  the  mother  liquor,  this  was  found 
to  be  entirely  free  of  nitrate  of  mercury,  showing  that  all  the  mercury 
had  been  precipitated  as  oleate  of  mercury.  The  oleate  was  now 
thoroughly  washed  with  cold  water  to  remove  the  nitrate  of  potassium, 
and  finally  pressed  with  a  pestel  to  remove  the  water  as  much  as  pos- 
sible. The  oleate  was  next  placed  in  a  tared  dish,  and  sufficient 
oleic  acid  was  added  to  make  the  whole  weigh  7000  grains.  The  dish 
was  then  placed  on  a  water-bath,  and  the  mixture  heated  to  140°  F., 
when  a  clear  solution  of  the  oleate  of  mercury  was  obtained  of  a  light 
yellowish  brown  color,  and  containing  five  per  cent,  of  the  red  oxide 
of  mercury. 
When  an  oleate  of  mercury  containing  ten  per  cent,  of  oxide  is  de- 
sired, all  that  is  requisite  is  to  double  the  above  quantities  of  ingre- 
dients, using  700  grs.  of  red  oxide  of  mercury,  &c,  &c,  and  after 
precipitating  and  washing  the  oleate,  adding  sufficient  oleic  acid  to 
make  the  whole  weigh  one  pound. 
The  solutions  of  oleate  of  mercury  prepared  from  the  commercial 
acid,  whether  by  the  above  process  or  by  dissolving  the  precipitated 
oxide  in  oleic  acid  by  heat,  are  prone  to  pass  from  the  liquid  to  a  gel- 
atinous and  finally  semi-solid  state,  caused  probably  by  further  oxida- 
tion of  the  combined  acid  and  also  by  its  partial  union  with  the  mono- 
acid  salt  first  formed,  and  in  experimenting  to  prevent  the  solidifica- 
tion, it  was  found  that,  when  adding  a  mixture  of  equal  parts  of  alco- 
hol and  oleic  acid,  instead  of  oleic  acid  alone,  to  the  precipitated  oleate 
of  mercury,  in  making  up  the  final  weight  of  the  preparation,  a  more 
liquid  product  was  obtained,  which  to  the  present  time  (seven  days), 
has  not  gelatinized. 
By  substituting  olive  oil  in  the  same  manner  for  the  oleic  acid,  to 
