THE  AMERICAN 
JOURNAL  OF  PHARMACY. 
JANUARY,  1886. 
SEVERAL  OFFICIAL  OINTMENTS. 
By  R.  Rother. 
When  hog's  fat,  of  the  body  cavity,  is  freed  from  investing  mem- 
branes by  a  process  of  fusion,  it  is  said  to  be  "  prepared,"  and  is  then 
officially  termed  lard.  Conventionally,  however,  the  unprepared 
I  internal  fat  is  also  called  lard.  But  this  confusion  of  terms  is  of  no 
serious  consequence,  since  the  connection  in  which  they  appear  gen- 
erally determines  the  one  that  is  meant.  Fat,  when  properly  puri- 
fied, is  not  exceedingly  prone  to  objectionable  changes.  Contamina- 
tion with  parts  of  the  original  integument,  but  particularly  the 
presence  of  water,  either  imperfectly  removed  or  fraudulently  added, 
induces  speedy  and  destructive  change.  In  course  of  time  and 
through  changing  temperature,  good  and  pure  lard  Avill  become  more 
or  less  granular,  but  still  remain  suitable  for  its  various  applications. 
The  action  of  water,  especially  when  aided  by  continued  warmth, 
deteriorates  lard  in  a  variety  of  ways.  One  of  the  most  undesirable 
and  conspicuous  of  these  results  is  the  so-called  rancidity.  This  is 
perhaps  partially  superinduced  by  a  species  of  fermentation,  the  de- 
graded product  being  either  coincidently  or- subsequently  still  further 
damaged  by  oxidation. 
Numerous  remedies  have  beeu  suggested  and  tested  in  order  to 
obviate  these  tendencies.  As  already  stated,  the  absence  of  water 
insures  a  more  extended  permanence.  In  many  instances,  however, 
its  presence  is  essential  for  other  reasons,  and  hence  the  application 
of  some  preservative  becomes  necessary.  Officially,  benzoin  is  used 
for  this  purpose,  which  seems  to  answer  very  well  in  the  majority  of 
cases.  There  is,  however,  a  limit  to  its  capacity  in  both  time  and 
conditions.  The  benzoic  acid  is  here  doubtless  the  active  agency,  as 
far  as  the  suppression  of  fermentation  is  concerned.  On  the  oxidation 
it  possibly  has  no  effect  to  the  extent  that  this  is  independent  of  the 
former.    A  benzoin-protected  fat  may  therefore  become  disqualified 
