562  U.  5.  Pharmacopoeial  Revision.       { AugusfYQlo' 
Unguentum  Acidi  Borici. — Paraffin  is  not  a  satisfactory  hardening 
agent  in  this  ointment.  White  wax  or  spermaceti  would  be  better. 
Paraffin  always  causes  the  ointment  to  become  granular. 
Unguentum  Aquae  Rosae. — The  expressed  oil  of  apricot  kernels 
should  be  recognized  by  the  Pharmacopoeia  and  used  in  this  oint- 
ment. This  expressed  oil  is  an  American  product,  seems  to  be  as 
satisfactory  as  expressed  oil  of  almond,  and  is  much  less  costly. 
As  a  matter  of  fact,  it  is  probably  used  in  the  preparation  of  this 
ointment  in  most  instances  at  the  present  time,  and  its  use  should  be 
acknowledged. 
Unguentum  Belladonnae. — ^The  addition  of  5  per  cent,  of  yellow 
wax  to  this  ointment,  replacing  an  equivalent  amount  of  benzoinated 
lard,  greatly  improves  the  product,  which  is  usually  too  soft. 
Unguentum  Chrysarobini. — Omit  the  directions  to  strain  the 
product,  as  this  seems  to  be  unnecessary  and  an  undesirable  manipu- 
lation. 
Unguentum  Diachylon. — It  ought  not  to  be  necessary  to  strain 
the  lead  plaster  and  petrolatum  in  this  ointment. 
Unguentum  Hydrargyri  Dilutum. — -This  ointment  has  been  found 
to  be  too  soft  in  consistence  for  normal  conditions.  By  replacing 
40  Gms.  of  the  petrolatum  with  yellow  wax,  a  more  satisfactory 
product  is  obtained. 
Unguentum  Hydrargyri  Nitratis. — The  formula  given  in  the 
Pharmacopoeia  is  satisfactory  for  small  lots  of  ointment.  In  the 
directions  it  should  be  made  more  clear  that  after  the  nitric  acid 
is  added  to  the  melted  lard,  the  heat  should  be  very  gradually  in- 
creased until  the  characteristic  reaction  is  complete.  It  is  important 
also  to  state  that  the  solution  of  mercuric  nitrate  should  be  incor- 
porated with  the  nitric  acid-treated  lard  before  it  has  become  cold. 
Unguentum  Hydrargyri  Oxidi  Flavi. — Ointment  of  yellow  mer- 
curic oxide  is  chiefly  used  for  ophthalmic  purposes  and  the  strength 
is  then  about  one  per  cent.  An  ointment  of  this  strength  should 
replace  the  official  ointment  or  be  introduced  as  a  "diluted  ointment 
of  yellow  mercuric  oxide."  This  should  be  made  with  a  petrolatum 
base. 
Unguentum  Zinci  Oxidi. — Persistent  efforts  have  been  made  to 
authorize  the  substitution  of  the  benzoinated  lard  in  this  ointment 
with  petrolatum.  Doubtless  superior  keeping  qualities  are  ex- 
hibited by  the  modification,  but  the  therapeutic  value  of  the  oint- 
ment is  changed.    It  has  been  repeatedly  observed  by  physicians 
