ON  BENZOINATED  LARD. 
63 
J,  and  reads  only  No.  3,  of  Jaeger  at  ten  inches.  All  objects 
look  dim.  This  dimness  is  not  the  effect  of  lachrymation, 
because  wiping  away  the  tears  does  not  better  the  vision. 
Accommodation  perfect.  There  are  no  muscse  nor  phosphenes  ; 
the  visual  field  normal.  By  the  opthalmoscope,  both  the  inverted 
and  upright  image,  no  material  change  discovered.  The  media 
clear,  the  optic  nerve  pink,  but  not  unlike  the  other  eye. 
"  The  external  inflammatory  symptoms  continued  for  one  day, 
and  then  the  eye  resumed  its  normal  condition,  both  in  appear- 
ance and  function. 
Dr.  P.  informed  me  that  a  similar  accident  hsfd  once  before 
occurred  to  him,  and  that  he  had  seen  an  account  of  such  an 
occurrence  to  a  Russian  chemist. 
The  impaired  sight  was  not  the  effect  of  the  irritation  of  the 
conjunctiva,  because  an  equal  degree  may  be  excited  by  the 
presence  of  a  foreign  particle,  without  any  amblyopia.  Dr.  P. 
and  myself  were  both  convinced  that  a  peculiar  poisonous  in- 
fluence was  exerted  on  the  retina,  produced  in  a  marvellously 
short  time,  by  the  simple  contact,  for  only  an  instant  of  the 
irritating  fumes  of  osmic  acid  with  the  surface  of  the  globe. — 
Am.  Journ.  Med.  Sci.,  October,  1868. 
ON  BENZOINATED  LARD. 
By  Thomas  Doliber. 
Query  25th.  What  is  the  best  process  of  benzoinating  lard  and  sim- 
ple ointments  ?  Can  benzoinated  lard  be  employed  for  mercurial  ointment, 
so  as  to  prevent  its  strong  tendency  to  become  rancid,  without  hurting 
its  medical  qualities  ;  and  in  what  other  ointments  may  this  form  of  lard 
be  advantageously  used  ? 
In  order  to  ascertain  the  best  process  of  benzoinating  lard,  the 
following  experiments  were  tried  : 
Two  troy-ounces  of  benzoin  were  digested  with  32  troy-ounces 
of  lard  in  a  water-bath,  in  accordance  with  the  formula  of  the 
Pharmacopoeia  for  preparing  ointment  of  benzoin.  The  residue 
of  the  benzoin,  after  being  dried  at  a  very  moderate  heat  between 
folds  of  bibulous  paper,  was  found  to  weigh  one  troy-ounce  and 
306  grains.  There  had  been  abstracted  from  it  174  grains  by 
the  lard,  provided  there  were  no  loss  by  evaporation  or  by  the  sub- 
