596 
Oleates. 
Am.  Jour.  Pharrru 
Dec,  1889. 
water,  slowly  add  the  soda  solution,  stirring  constantly  until  the  acid 
is  entirely  neutralized,  and  a  small  portion  of  the  resulting  soap  dis- 
solved in  alcohol  yields  but  a  faint  pink  tint  on  the  addition  of  a  few 
drops  of  alcoholic  solution  of  phenol  phthaleine.  Dissolve  the  resulting 
soap  in  three  (3)  pints  of  warm  water  and  filter  if  necessary.  Dissolve 
the  zinc  sulphate  in  one  (1)  pint  of  water  and  filter.  Warm  the  solu- 
tions co  43°  C.  (110°  F.),  and  slowly  add  the  zinc  sulphate  solution 
to  the  soap  solution,  stirring  constantly.  Collect  the  precipitate  on  a 
moist  filter,  wash  thoroughly  with  distilled  water  and  finally  dry  on 
bibulous  paper  at  a  temperature  not  exceeding  38°  C.  (100°  F.). 
In  the  above  formula,  there  is  ordered  an  excess  of  zinc  sulphate  as 
this  tends  to  more  readily  separate  the  oleate  produced.  It  is  impor- 
tant that  the  temperature  of  the  solutions  on  precipitating  should  be 
maintained  at  100°-110°  F.  At  this  temperature  the  oleate  on  dry- 
ing is  obtained  in  white  friable  masses  to  powder  which  it  is  only 
necessary  to  rub  through  a  sieve.  If  a  temperature  much  lower  than 
this  is  used  the  resulting  oleate  is  in  curdy  masses  which  are  glutinous 
to  the  touch  and  almost  impossible  to  pulverize.  If  precipitated  at 
a  higher  temperature  the  result  is  a  fused  mass  of  oleate  of  a  greasy 
nature,  which  can  only  be  dried  and  pulverized  with  difficulty  and 
the  resulting  powder  is  gritty.  As  thus  obtained,  oleate  of  zinc  is  a 
nearly  white,  impalpable,  unctuous,  slippery  powder,  fusing  at  75°  C.r 
very  soluble  in  ether,  carbon  bisulphide,  chloroform,  and  benzol, 
somewhat  less  soluble  in  turpentine,  petroleum  ether  and  alcohol. 
The  yield  was  1,122  grains,  theoretical  yield  being  1,115  grains. 
The  excess  most  likely  being  due  to  water  retained  at  100°  F. 
Plumbi  Oleas. 
Oleate  of  Lead,  Pb(C18H3302)2. 
Take  of — 
Oleic  acid  1,000  grains. 
Soda     160     "     or  q.  s. 
Alcohol   6  fluidrachms. 
Lead  acetate   675  grains. 
Water,  a  sufficient  quantity. 
Saponify  the  oleic  acid  as  directed  in  the  formula  for  zinc  oleate,  and 
dissolve  the  resulting  soap  in  three  (3)  pints  of  warm  water  and  filter. 
Dissolve  the  lead  acetate  in  two  pints  of  water,  adding  a  few  drops  of 
acetic  acid  if  necessary  to  produce  a  clear  solution,  and  filter.  Warm 
the  solutions  and  add  the  lead  acetate  solution  slowly  to  the  soap  solu- 
tion, stirring  constantly.    Collect  the  mass  on  a  strainer,  wash  and  dry. 
