224 
Oil  Resorcin. 
/  Am,  Jour.  Pharm. 
(      May,  1881. 
bromine,  tetrabrom-fliiorescein  is  produced,  the  potassium  salt  of 
which,  eosin,  CooHgKgBr^O^,  is  remarkable  for  the  magnificent  rose-red 
color  of  its  aqueous  solution,  accompanied  by  a  green,  or,  when  the 
solution  is  very  dilute,  yellow  fluorescence.  The  azo-compounds  of 
resorcin,  most  of  which  are  also  line  coloring  matters,  have  quite 
recently  been  studied  by  P.  Weselsky  ("  Ber.  d.  deutsch  chem.  Ges.," 
1881,  p.  50),  the  diazo-resorcin  being  formed  by  the  action  of  pure 
nitrogen  tetroxide  on  resorcin  in  ether  ial  solution,  as  shown  by  the 
equation  3C6H,02+^204=C\8H,oNA+4H20. 
It  forms  brown,  granular  crystals  with  a  green  metallic  lustre, 
which  are  dissolved  by  alkalies  with  a  magnificent  blue  violet  color. 
Finally  may  be  mentioned  the  so-called  resorcin- black  (see  this  journal, 
1876,  p.  379),  which  is  produced  by  the  addition  of  a  solution  of 
cupric  sulphate  and  ammonia  to  an  aqueous  solution  of  resorcin. 
In  regard  to  the  economic  and  therapeutic  applications  of  resorcin, 
the  following  abstracts  quoted  from  Dr.  Justus  Andeer,  as  contained 
in  the  "  Scientific  American,"  No.  9,  1881,  p.  129,  and  in  most  of  the 
recent  medical  journals,  will  be  found  of  interest.  Chemically  pure 
resorcin,  which  withstands  the  light,  when  in  a  one  per  cent,  solution 
stops  the  development  of  fungi  and  mould.  This  has  been  proven 
not  only  by  artificial  experiments  in  the  laboratory,  but  also  chemically 
on  the  appearance  of  symptoms  of  disease.  A  one  per  cent,  solution 
will  not  prevent  fermentation,  but  only  retard  it  in  favorable  cases. 
To  stop  it  completely  requires  a  comparatively  strong  solution  of 
to  2  per  cent.  What  seems  deserving  of  special  remark  is  that  abso- 
lutely pure  resorcin,  in  any  degree  of  concentration,  coagulates  albumen 
and  precipitates  it  from  solution.  On  this  account  the  author  con- 
siders it  an  excellent  caustic  to  remove  unhealthy  tissue.  In  crystals  it 
cauterizes  as  powerfully  as  lunar  caustic,  but,  as  stated,  without  pain, 
nor  does  it  form  metallic  albuminates,  which  are  insoluble  or  difficult 
of  solution,  causing  a  scar ;  in  a  comparatively  short  time,  3  or  4  days, 
the  skin  regains  its  natural  appearance. 
As  a  caustic  it  is  valuable  in  catarrhal,  tuberculate  and  syphilitic 
sores,  in  which  cases  it  is  best  used  in  the  form  of  crystals  applied  to 
the  excrescences,  particularly  on  mucous  membranes,  removing  them 
painlessly,  and  restoring  tlie  membrane  in  3  or  4  days  to  its  normal 
condition.  In  the  form  of  powder  it  is  said  to  be  an  efficient  remedy 
in  diphtheritic  affections.  It  is  an  excellent  remedy  by  way  of  inhala- 
tion in  the  form  of  spray,  neither  irritating  the  eyes  of  the  operator 
