Amjui°yuri9i4arm*}      Bichloride  of  Mercury  Tablets.  317 
between  the  medicinal  tablets  used  so  extensively  for  oral  adminis- 
tration and  such  poisonous  tablets  intended  for  external  use.  The 
safeguarding  of  life  is  the  first  and  principal  consideration,  and  this 
warrants  the  coining  of  a  new  title  that  shall  distinguish  the  latter 
as  a  separate  and  distinct  class.  For  this  purpose  I  propose 
Toxitabellce  as  a  distinctive  class  title,  and  as  the  official  title  for 
these  tablets,  "  Toxitabellse  Hydrargyri  Chloridi  Corrosivi,"  and  as 
the  English,  "  Poison  Tablets  of  Corrosive  Mercuric  Chloride." 
The  foreign  formulas  follow  the  formula  of  Angerer  in  directing 
equal  parts  of  mercuric  chloride  and  sodium  chloride.  The  Ameri- 
can manufacturers  generally  claim, on  their  labels  to  adhere  to  the 
Wilson  formula.  Tablets  containing  the  proportion  of  ammonium 
chloride  directed  in  this  latter  formula  are  prone  to  change  on  keep- 
ing. They  deliquesce  in  humid  atmospheres,  and  the  solubility  also  de- 
teriorates with  age.  For  these  reasons,  some  of  the  manufacturers 
have  already  substituted  sodium  chloride  for  part  of  the  ammonium 
chloride.  One  manufacturer  advises  that  he  has  found  preferable 
a  mixture  of  corrosive  sublimate  7.3  parts,  ammonium  chloride  2.7 
parts,  sodium  chloride  5  parts.  The  entire  replacement  of  the 
ammonium  chloride  by  the  sodium  chloride  will  doubtless  yield  a 
more  stable  and  soluble  tablet,  and  this  change  should  be  adopted 
in  the  pharmacopceial  formula. 
The  coloring  of  bichloride  of  mercury  antiseptic  tablets  was 
originally  proposed  not  only  to  make  them  distinct  in  color  from 
other  tablets  of  the  same  shape  and  size,  but  the  primal  idea  was 
to  obtain  a  solution  that  would  have  a  distinct  color  and  not  be 
mistaken  and  administered  for  harmless  medications  or  water.  Such 
accidents  had  occurred,  and  to  prevent  recurrence  Angerer  proposed 
as  an  additional  safeguard  that  the  solutions  should  be  colored.  It 
has  been  difficult  to  select  a  red  dye  that  would  possess  sufficient 
tinctorial  strength  so  that  only  a  minute  quantity  would  be  required 
and  at  the  same  time  be  permanent  and  not  altered  by  the  action  of 
the  chemicals  nor  fade  on  keeping.  This  problem  has  confronted 
the  manufacturers  and  has  been  the  subject  of  considerable  experi- 
mentation on  the  part  of  the  writer. 
Eosin  in  the  quantity  proposed  yields  a  tablet  that  is  distinctly 
pink,  but  when  in  solution  (1  HgCl2  in  1000)  does  not  show  a  dis- 
tinct color.  This  practical  difficulty  with  the  red  dyes,  their  variable 
shades,  and,  moreover,  the  fact  that  confections  are  frequently  of 
this  color  and  liquid  medicines  are  likewise  commonly  some  shade 
