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A  n tiseptic  Materials. 
Am.  Jour.  Pharm. 
Nov.,  1890. 
from  precipitation  of  the  oils,  yet,  on  the  further  addition  of  water,  it 
again  becomes  transparent. 
An  antiseptic  which  of  late  has  attracted  much  attention  is 
that  first  introduced  by  Dr.  E.  P.  Bernardy  ( 1886),  of  this  city.  It  is 
a  solution  of  mercuric  iodide  (/  part)  with  sufficient  potassium  iodide 
to  dissolve.  Theoretically,  it  would  require  about  three-fourths  of 
the  quantity  of  the  mercurial  salt  used,  but  in  practice  he  uses  equal 
parts,  so  as  to  prevent  the  possibility  of  subsequent  precipitation  of 
mercuric  iodide  on  further  dilution  with  water. 
It  is  claimed  that  T^F  solution  of  this  compound  is  equivalent 
in  germicidal  strength  to  a  ^  qVo"  s°luti°n  of  mercuric  chloride,  and 
experiments  made  by  Bernardy,  Krassowski  and  others  would  seem 
to  justify  the  claim.  Further,  Dr.  Bernardy  informs  the  writer  that 
in  his  experiments  he  found,  with  a  solution,  no  precipitation, 
upon  adding  it  to  blood  serum,  and  Mr.  Listed  states  that  red  mer- 
curic iodide  is  freely  soluble  in  200  parts  of  blood  serum  and 
remains  most  actively  antiseptic. 
One  drawback  to  its  more  general  employment  is  its  ineligibility. 
Mercuric  iodide  and  potassium  iodide  cannot  be  compressed 
together  in  tablet  form  on  account  of  the  deliquescent  nature  of  the 
combination,  and  it  is  not  advisable  to  add,  as  has  been  sometimes 
done  to  obviate  that  result,  ammonium  chloride,  for  fear  of  ultimate 
conversion  of  the  mercuric  iodide  into  mercuric  chloride  and  ammo- 
nium iodide.  The  best  way  would  seem  to  be  to  compress  separate 
tablets  of  grains,  and,  on  using,  dissolve,  one  of  each,  in  a  small 
quantity  of  water  first,  and  then  add  the  balance  of  water  to  make 
the  quart. 
In  introducing  this  antiseptic,  the  chemical  error  has  been 
made  of  calling  it  "  biniodide  of  mercury."  It  is  nothing  of  the  sort. 
By  chemical  addition,  a  very  deliquescent  and  entirely  different 
compound  is  formed,  namely,  potassio-mercuric  iodide  (2  KI.  Hgl2). 
We,  as  pharmacists,  know  what  a  strongly  decomposing  influence 
this  solution,  in  the  form  of  "  Mayer's  Reagent,"  has  upon  alkaloidal 
solutions — even  greater  than  a  solution  of  mercuric  chloride,  and 
a  possible  explanation  of  the  high  germicidal  value  of  potassio- 
mercuric  iodide  may  be  found  in  that  fact,  with  also  Dr.  Van 
Arsdale's  (Annals  of  Surgery)  explanation  of  the  antiseptic  action  of 
iodoform,  remembering  that  ptomaines  are,  in  a  strictly  chemical 
sense,  alkaloids.    He  says  that  "  the  germicide  power  of  iodoform 
