2  Oleate  of  Mercury  and  Morphia.     { AMjaJn0U?;  5?£*- 
192  grains  of  oxide  of  mercury,  corresponding  to  177*7  grains  of 
metallic  mercury,  heated  with  ten  times  the  weight  of  oleic  acid, 
gave  the  following  reductions  : 
At  300°  F.  amount  of  reduced  Hg,   .  .    175  grains. 
At  280°  F.         "  "  .         152  " 
At  212°  F.         "  "  69  " 
At  200°  F.         "  "  .  35  " 
Between  200°  and  180°  F.  the  amount  of  reduction  varied  between 
20  and  40  grains,  according  to  shorter  or  longer  exposure  to  heat ; 
but  I  have  been  uusuccessful  in  effecting  a  solution  unaccompanied 
by  reduction,  This  makes  it  necessary  to  estimate  the  strength  of 
each  fresh  lot  of  solution. 
The  strength  of  the  preparation  as  prescribed  by  different  physi- 
cians has  varied  from  twenty  per  cent,  to  two  per  cent,  of  oxide  of 
mercury,  with  variable  quantities  of  morphia ;  but  of  late  a  uniform 
strength  of  six  per  cent,  of  oxide  of  mercury  and  two  per  cent,  of 
morphia  is  deemed  sufficient  for  most  purposes,  and  the  following  is 
the  process  which  I  employ  for  its  preparation  : 
Expose  the  commercial  oleic  acid  to  a  temperature  of  40-50°  F.^ 
and  express  the  liquid  portion,  which  is  oleic  acid,  deprived  of  the 
greater  portion  of  the  accompanying  solid  acids.  Take  of  oleic  acid,, 
prepared  as  above,  1536  grains  ;  oxide  of  mercury,  perfectly  dry, 
192  grains.  Rub  the  oxide  in  a  mortar  with  some  of  the  oleic  acid 
to  a  smooth  paste ;  add  the  remainder  of  the  acid ;  place  the  mortar 
on  a  water  bath,  and  promote  solution  by  frequently  stirring,  taking 
care  not  to  allow  the  temperature  to  exceed  200°  F. 
As  soon  as  all  the  oxide  has  disappeared,  or  rather  as  soon  as  the  un- 
dissolved residue  is  of  a  pure  gray  color,  remove  the  mortar  from  the 
water  bath  and  allow  it  to  stand  for  twenty-four  hours.  Then  pour 
off  the  clear  solution  into  a  tared  capsule  ;  wash  the  residue  thoroughly 
with  ether  and  add  the  washing  to  the  liquid  in  the  capsule.  Expose 
the  latter  to  a  very  gentle  heat,  until  all  the  ether  has  evaporated  and 
weigh.  The  residue,  after  being  properly  washed  and  carefully  dried 
(without  heat),  may  be  weighed  as  metallic  mercury,  which  is  in  prac- 
tice sufficiently  correct. 
Supposing  the  weight  of  the  obtained  solution  to  be  1698  grains 
and  the  weight  of  the  reduced  mercury  to  be  thirty  grains  (assuming 
therefore  that  there  has  been  no  loss  incurred  during  heating  and 
during  the  subsequent  washing  of  the  residue,  whilst  in  practice  a. 
