152    PRESERVATION  AND  DISPENSING  OF  OINTMENTS,  ETC. 
Since  accepting  this  query,  I  have  induced  one  of  our  glass 
dealers  to  introduce  a  style  of  jar  with  tinned  iron  cover,  (a  sam- 
ple of  which  is  now  presented,)  which  answers  a  good  purpose, 
although  objectionable  on  account  of  the  imperfect  manner  in 
which  the  mouth  is  finished.  This  jar,  of  the  size  presented,  can 
be  furnished  to  the  trade  at  about  seven  or  eight  dollars  per 
gross. 
"  What  is  the  best  plan  for  keeping  ointments  and  cerates  in  the  dis- 
pensing shop,  so  as  to  retard  their  tendency  to  oxidation?" 
To  make  an  ointment  that  will  keep,  it  is  of  primary  impor- 
tance that  the  materials  used  should  be  of  good  quality,  especially 
lard.  This  article  is  sometimes  adulterated  by  an  admixture  of 
water,  which  answers  the  double  purpose  of  rendering  the  lard 
white  and  increasing  its  weight.  The  amount  of  water  intro- 
duced varies  in  proportion,  according  to  the  conscience  of  the  op- 
erator. This  variety  of  lard  should  be  carefully  avoided  by  the 
Pharmaceutist,  as  the  ointments  and  cerates  into  which  it  enters 
undergo  oxidation  rapidly,  and  soon  acquire  a  degree  of  rancidity 
which  is  offensive  to  persons  in  health,  and  of  course  much  more 
so  to  the  sick.  What  is  called  leaf  lard,  prepared  at  farm  houses, 
and  which  is  used  by  some  Pharmaceutists,  is  undoubtedly  the 
best  for  preparing  ointments  ;  but  when  this  cannot  be  procured, 
the  article  known  in  commerce  as  pressed  lard,  answers  a  good 
purpose ;  being  prepared  from  firm  lard  in  the  first  instance,  it 
is  not  liable  to  the  objection  of  containing  water. 
Another  advantage  gained  in  the  use  of  pressed  lard  for  many 
ointments  is,  that  the  quantity  of  wax  may  be  considerably  re- 
duced, which,  on  the  score  of  economy,  is  of  some  importance ; 
and  as  wax  is  used  merely  to  give  consistence  to  the  ointment,  it 
is  a  question  whether  an  ointment  prepared  from  pressed  lard  is 
not  superior  to  one  into  which  a  large  proportion  of  wax  enters, 
on  the  ground  of  being  more  homogeneous. 
The  use  of  benzoin  in  the  preparation  of  ointments  and  ce- 
rates undoubtedly  tends  to  retard  oxidation.  It  is  best  used  in 
the  form  of  tincture  made  in  the  proportion  of  four  ounces  to 
the  pint  of  alcohol,  two  fluid  drachms  of  which  are  sufficient  for 
sixteen  ounces  of  ointment. 
Having  volunteered  the  foregoing  remarks  in  regard  to  the 
