28  On  the  Oleo-Stearates,  etc.  {AV*™;wT~ 
at  the  last  the  heat  was  raised  for  about  ten  minutes  to  low  redness. 
The  charcoal  proved,  on  analysis,  to  contain  3*2  per  cent,  of  iodine, 
equal  to  19*64  per  cent,  of  the  iodine  contained  in  the  specimen  before 
its  conversion  into  charcoal.  Thus,  about  four-fifths  of  the  iodine 
contained  in  the  strongly-dried  iodized  starch  is  driven  off  (though 
not  as  a  free  iodine)  by  charring  at  a  red  heat,  and  a  fifth  of  the  iodine 
remains  with  the  charcoal  formed. — Qhem.  News,  Nov.  14,  1873. 
ON   THE  OLEO-STEARATES,  AND   PARTICULARLY    ON  THE 
OLEO-STEARATE  OF  ZINC, 
By  Arthur  Yan  Harlingen,  M.  D. 
Translated  from  the  Bulletin  Generate  de  Therapeutiqut,  Sept.  1873. 
We  desire  to  call  the  attention  of  practitioners  to  the  advantages 
which  these  compounds  present,  both  as  entering  into  particular 
pharmaceutical  preparations,  and  as  to  the  therapeutic  results  which 
may  be  hoped  for  from  their  use. 
Oleo-stearates  for  rather  oleo-stearo-margarates)  are  salts  which 
have  as  bases  oxides  of  the  various  metals,  and  as  acids  the  oleic, 
stearic,  and  even  margaric  ;  and  which  are  extracted  from  fatty  sub- 
stances by  saponification. 
Two  processes  may  be  employed  for  the  preparation  of  these  salts  : 
one,  which  is  direct,  consists  in  mingling  in  presence  of  a  certain 
quantity  of  water  the  different  oxides  which  it  is  desired  to  combine, 
and  the  acids,  or  rather  the  natural  fatty  substances  which  are  found 
in  combination  with  glycerin  under  the  names  of  olein,  stearin,  and 
margarin.  In  this  process  the  action  of  heat  is  often  necessary,  in 
order  that  the  combination  may  be  more  easily  effected. 
This  method  is  similar  to  that  by  which  almond  soap  (oleate  of 
soda),  white  soap,  and  lead  plaster  (oleo-stearo-margarate  of  lead)  are 
prepared. 
In  other  cases,  and  particularly  where  the  oxide  which  is  to  enter 
into  combination  is  very  slightly  alkaline,  or  of  feeble  solubility  in 
water,  and  where,  on  the  other  hand,  the  oleo-stearate  is  insoluble  in 
the  same  vehicle,  it  is  necessary  to  have  recourse  to  a  second  process, 
which  permits  of  obtaining  the  salt  indirectly  and  by  double  decom- 
position. 
It  is  by  this  process  that  the  oleo-stearates  of  iron,  copper,  mercury, 
etc.,  and  of  the  various  alkaloids,  are  obtained. 
