Am.  Jour-  Pharm. 
Dec.,  1SS9. 
Oleates. 
599 
The  aqueous  solution  decanted  from  the  precipitate  gave  no  indica- 
tions of  mercury  with  solution  of  potassa  or  potassic  iodide,  proving 
the  complete  precipitation  of  the  metallic  salt. 
The  sample  shown,  marked  No,  1,  was  prepared  over  four  months 
ago,  and  has  been  purposely  kept  in  a  warm  part  of  the  store  in  a 
flint  vial,  the  stopper  being  occasionally  removed.  The  surface  exposed 
to  the  light  now  shows  a  reduction  of  the  mercury,  which  was  not 
very  marked  until  three  months  of  summer  weather  had  elapsed  since 
the  preparation.    The  second  sample  was  prepared  about  a  week  ago. 
Bismuthi  Oleas. 
Oleate  of  Bismuth,  Bi(C18H3302)3. 
The  most  difficult  oleate  to  prepare  by  double  decomposition  is  the 
bismuth  oleate.  The  tendency  of  bismuth  solutions  to  precipitate 
oxy  salts  unless  in  decidedly  acid  solutions,  and  the  decomposition  of 
the  oleate  solution  used  by  the  acid  solution  renders  it  almost  impossi- 
ble to  thus  make  this  oleate.  Mr.  H.  B.  Parsons  (Joe.  cit.)  attempted 
to  overcome  this  difficulty  by  using  a  solution  of  crystallized  nitrate 
of  bismuth  in  glycerin.  Even  this  is  apt  to  yield  unsatisfactory  re- 
sults. I  have  obtained  more  satisfactory  results  by  saponifying  the 
acid  with  oxide  of  bismuth.  On  heating  oxide  of  bismuth  with  oleic 
acid  but  a  very  small  portion  is  dissolved  ;  on  boiling  them  together 
with  water,  however,  saponification  takes  place.  Owing  to  the  vari- 
ability of  commercial  subnitrate  of  bismuth  (see  Amer.  Jour.  Phar., 
1888,  p.  385)  good  results  were  not  obtained  by  taking  a  definite  weight 
of  that  salt  and  precipitating  the  hydrated  oxide  from  its  solution  in 
nitric  acid.  The  quantity  of  hydrate  varied  so  much  as  to  yield  on 
boiling  with  the  calculated  quantity  of  oleic  acid  an  oleate  of  too  soft  a 
consistence.  For  these  reasons  I  prefer  to  use  an  oxide  dried  at  212°F. 
The  following  is  the  formula  I  prefer. 
Take  of— 
Bismuth  oxide  dried  at  100°  C.  (212°  F,)  until  it  ceases  to  lose 
water  1  troy  oz. 
Oleic  acid  3  troy  oz.  and  295  gr. 
Water,  a  sufficient  quantity. 
Rub  the  oxide  of  bismuth  to  a  fine  powder,  and  thoroughly  mix  it 
with  the  oleic  acid  in  a  capacious  vessel,  add  two  pints  of  water  and 
boil  the  mixture,  replacing  the  water  as  it  evaporates,  and  stirring  fre- 
quently until  complete  saponification  has  taken  place  and  a  small 
quantity  of  the  mass  dropped  into  cold  water  yields  an  ointment-like 
