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PREPARATION  OF  IODIDE  OF  CALOMEL. 
to  endeavor  to  decide  this  point,  or  at  least  to  try  and  make 
some  advance  towards  a  decision. 
On  treating  greenish  yellow  feathers  with  hot  acetic  acid,  we 
obtain  a  solution  of  the  same  color,  only  a  little  paler.  By 
evaporating  it,  and  then  treating  it  with  alcohol,  we  have  like- 
wise a  solution  of  the  same  color.  Is  this  solution  of  the  pig- 
ment zooverdine  f  I  am  not  quite  sure  of  this,  as  the  color  is 
not  decisive. 
A  pale  yellow  solution  is  likewise  obtained  by  treating  the 
feathers  of  the  Ariolus  galbula  with  acetic  acid  ;  but  this  solution 
loses  color  rapidly,  and  I  have  not  been  able  as  yet  to  isolate  the 
zoofulvine. — London  Chemist,  December,  1857,  from  Oomptes 
Hendus. 
ON  THE  PKEPARATION  OF  IODIDE  OF  CALOMEL  (IODURE  DE 
CHLORURE  MERCUREUX.) 
By  M.  Gobley. 
The  chemical  compound  called  iodide  of  calomel,  discovered 
in  1847,  by  M.  Boutigny,  was  prepared  by  mixing  protochloride 
of  mercy  and  iodine  in  the  relation  of  one  equivalent  of  iodine 
and  two  equivalents  of  the  proto-chloride,  and  it  consists  of  a 
mixture  of  calomel  with  biniodide  and  bichloride  of  mercury.  It 
is  consequently  less  active  than  the  two  latter  salts,  but  more 
active  than  the  protiodide  and  the  protochloride,  and  is  very 
much  celebrated  in  the  treatment  of  certain  affections  of  the 
skin,  particularly  in  acne  rosacea.  M.  Gobley  endeavors  to 
render  the  process  of  M.  Boutigny  more  practical  and  more  easy 
of  application.  He  takes  iodine  reduced  to  powder  in  a  mortar, 
and  mixes  it  with  calomel,  and  then  introduces  the  mixture  into 
a  small  glass  retort.  This  is  then  placed  upon  a  sand  bath,  and 
some  moments  afterwards  the  mass  is  seen  to  assume  at  first  a 
greenish  tint,  and  then  enter  into  fusion.  The  retort  is  with- 
drawn, and  the  mass  soon  solidifies ;  it  is  at  first  greenish,  then 
in  the  air  becomes  gradually  red,  and  at  last  it  remains  so.  The 
iodide  of  calomel  is  employed  in  pills  and  as  a  pommade  ;  the 
former  are  prepared  by  mixing  it  altogether  with  gum  arabic, 
crumb  of  bread,  and  orange-flower  water  ;  the  latter  is  made  by 
mixing  it  in  powder  with  lard. 
