43 8  Uuguentum  Hydrargyri  Nitratis.    { Am 'sllZ^g™' 
A  sample  of  citrine  ointment,  prepared  by  the  writer  with  lard  oil 
in  place  of  lard,  and  kept  excluded  from  contact  of  air  at  a  temper- 
ature ranging  between  400  and  6o°F.,  did  not  show  any  sign  of  change 
after  more  than  six  weeks. 
It  is  somewhat  softer  than  simple  cerate,  and  easily  worked  when 
rubbed  upon  a  slab. 
The  writer  feels  assured  that  if  the  following  formula  and  precautions 
for  making  citrine  ointment  be  generally  adopted  that  good  results  must 
follow,  and  citrine  ointment  can  henceforth  be  classed  among  the 
"Elegant  Pharmaceutical  Preparations." 
R    Mercury,  .....  Jjiss 
Nitric  acid  (sp.  gr.  1*420),  .  .  .  ^iiiss 
Best  lard  oil,         .....  ^xviss 
Heat  the  lard  oil  in  a  porcelain  vessel  to  adout  200°F.,  and  add 
nitric  acid  ij  troyounce,  a  little  at  a  time,  with  constant  stirring  by 
means  of  a  glass  rod,  until  combined  before  more  acid  is  added.  Regu- 
late the  heat  so  as  to  keep  up  a  mild  boiling.  Finally,  set  aside  to  cool 
slowly.  In  the  meantime,  put  the  mercury  into  a  chemical  flask,  add 
the  remainder  of  the  nitric  acid,  and  dissolve  by  aid  of  heat  in  the  open 
air.  When  the  oxidized  oil  commences  to  congeal  add  the  mercurial 
solution  to  it,  and  stir  until  it  is  cold.  Put  the  finished  product  in  1  or 
2  oz.  pots,  and  keep  in  a  cool  place,  and  excluded  from  light  and  air.. 
UNGUENTUM  HYDRARGYRI  NITRATIS. 
By  William  B.  Humrich,  Ph.G. 
From  an  Inaugural  Essay. 
From  his  experiments,  the  writer  concluded  that  elaidin  would  be 
the  proper  base  for  the  ointment  of  nitrate  of  mercury,  and  proceeded 
to  make  that  compound  from  both  expressed  oil  of  almond  and  olive 
oil,  as  follows : 
In  each  case  the  oil  was  heated  over  a  water-bath  to  the  temper- 
ature of  200°F.,  and  nitric  acid  added,  several  drachms  at  a  time,  until 
ten  drachms  of  acid  had  been  used  to  each  fluidounce  of  oil.  During 
the  process  considerable  effervescence  occurred  and  copious  red  fumes 
were  evolved.  The  heat  was  continued  for  a  short  time  after  effer- 
vescence ceased,  in  order  to  evaporate  the  water. 
The  elaidin  prepared  from  almond  oil  was  of  a  deep  yellow  color, 
