AmMarchj908!m'}    Notes  on  Compound  Resorcinol  Ointment.  121 
30  per  cent,  of  water,  which  would  normally  be  present  in  the 
hydrous  wool-fat,  and  incorporating  this  solution  with  the  right 
amount  of  warmed  anhydrous  wool-fat. 
The  next  difficulty  which  confronts  the  manipulator  is  the  addition 
of  the  melted  paraffine  and  petrolatum  to  the  mixture  of  resorcinol, 
zinc  oxide,  bismuth  subnitrate,  and  hydrous  wool-fat. 
My  experience  at  this  point  in  the  preparation  of  the  ointment 
I  find  to  be  similar  to  many  others.  When  this  melted  mixture  of 
paraffine  and  petrolatum  is  added  to  the  remainder  of  the  ointment, 
whether  it  be  in  a  mortar  or  on  an  ointment-slab,  the  paraffine  will 
separate  in  small  white  particles,  owing  to  its  having  a  much  higher 
melting-point  than  the  petrolatum,  and,  consequently,  cooling  more 
quickly,  and  when  this  condition  is  experienced  the  usual  remedy 
which  the  pharmacist  adopts  is  that  of  rubbing  small  portions  at  a 
time  until  they  are  uniform.  This  involves  much  labor  and  the 
result,  at  best,  is  unsatisfactory.  Having  spoken  with  a  number  of 
pharmacists,  I  understand  that  this  experience  is  common,  and  the 
strict  following  of  the  directions  given  in  the  N.F.  for  its  prepara- 
tion will,  I  believe,  always  be  unsatisfactory. 
After  a  number  of  experiments  the  following  modification  of  the 
N.F.  directions  for  preparing  this  ointment,  without  changing  the 
ingredients,  is  offered  :  Dissolve  the  resorcinol  (6  parts)  in  10^  parts 
of  water,  with  the  aid  of  a  little  heat.  Warm  24^2  parts  of  anhy- 
drous wool-fat  contained  in  a  porcelain  dish  on  a  water-bath,  using 
just  a  sufficient  amount  of  heat  to  soften  the  wool-fat,  and  add 
the  solution  ot  resorcinol,  stirring  continuously  ;  then  add  the 
6  parts  of  bismuth  subnitrate  and  6  parts  of  zinc  oxide,  continuing 
trituration  until  perfectly  smooth.  Having  melted  the  paraffine  and 
petrolatum  together,  add  the  mixture  to  the  warmed  wool-fat,  to 
which  the  other  ingredients  have  been  added,  stirring  continuously. 
Finally,  incorporate  the  12  parts  of  oil  of  cade,  and  continue  the 
stirring  until  the  ointment  is  firm. 
An  ointment  made  in  this  way  is  perfectly  smooth,  and  although 
the  detail  here  given  may  seem  unnecessary  to  those  who  have  not 
tried  this  ointment,  one  experiment  with  each,  which  may  require 
two  hours  of  hard  work  to  accomplish  by  the  N.F.  method,  and 
fifteen  minutes  by  the  proposed  method,  resulting  in  a  superior 
product,  should  convince  the  most  skeptical  of  the  need  for  a  change 
in  the  N.F.  directions. 
