262         YELLOW  AMORPHOUS  OXIDE  OF  MERCURY,  ETC. 
filtered  from  this  precipitate  is  dextro-rotatory  and  contains  sugar, 
the  presence  of  which  may  be  recognized  by  cupro-potassic  tar- 
trate. 
Coniferine  presents  a  characteristic  reaction.  Whilst  Salicine 
is  turned  red  by  concentrated  sulphuric  acid,  Coniferine  turns  a 
deep  violet ;  on  adding  afterwards  a  little  water,  a  precipitate  is 
formed,  which  colors  the  liquid  a  deep  indigo  blue,  and  which  is 
probably  the  same  substance  as  mentioned  above. 
Cold  hydrochloric  acid  dissolves  Coniferine  without  change  of 
color,  but  if  the  solution  formed  is  heated  and  evaporated,  the 
same  indigo-blue  precipitate  is  formed. 
Sulphuric  acid  is  a  good  reagent  for  recognizing  this  substance. 
It  is  sufficient  to  touch  a  fresh-made  cut  in  a  tree  of  the  family 
Conifers,  in  order  to  ascertain  the  presence  of  Coniferine. — Lon- 
don Pliarm.  Journ.,  February,  1867,  from  Journal  f.  JPraJct. 
Chemie,  t.  xcvii.  p.  243. 
ON  THE  YELLOW  AMORPHOUS  OXIDE  OF  MERCURY  AND 
ITS  APPLICATION  IN  CONJUNCTIVITIS  AND  CORNEI- 
TIS  PHLYCTENULOSA. 
By  Dr.  Pagenstecher,  Wiesbaden. 
Red  precipitate,  the  red  oxide  of  mercury,  has  hitherto  played 
an  important  part  in  the  treatment  of  the  superficial  diseases  of 
the  eye,  and  ih  many  instances  constitutes  the  basis  of  several 
secret  popular  remedies.  It  is  especially  used  in  various  kinds 
of  blepharitis,  in  the  form  of  an  ointment,  and  valued  by  every 
oculist  as  a  very  favorite  remedy.  In  diseases  of  the  conjunc- 
tiva, and  cornea  too,  when  the  object  of  the  surgeon  was  to  pro- 
duce a  stimulant  or  alterative  effect,  we  find  in  the  "  Pharmaco- 
poeia "  several  compound  ointments  of  this  description  recom- 
mended. But  these  ointments  mostly  possess  the  disadvantage 
of  being  inapplicable  to  all  these  forms  of  disease,  and  especially 
so  to  conjunctivitis  and  corneitis  phlyctenulosa,  being  often  found 
to  irritate  too  much.  Numerous  and  prolonged  trials  that  I  in- 
stituted years  ago,  proved  to  me  that  the  red  precipitate  in  ordi- 
nary use  was,  from  its  crystalline  form,  not  sufficiently  finely 
divided,  and  consequently  did  not  act  uniformly  on  the  surface 
of  the  diseased  membranes ;  very  often,  too,  got  retained  in  the 
