302  UNGTJENTUM  HYDRARGYRI  OXIDI  RUBRI. 
the  glass,  as  I  before  stated,  and  the  apparent  different  modifica- 
tions of  the  impurity  may  be  caused  bj  the  different  percentage 
of  acid  from  which  the  crystals  are  deposited.  Concerning  the 
yellowish  deposit,  I  am  not  certain  that  there  is  a  necessary  con- 
nection between  it  and  the  sulphate  of  lime  ;  but  the  precipita- 
tion of  both  must  have  been  simultaneous  in  the  case  I  wrote 
about. 
Yours  very  truly,         J.  C.  Wharton. 
Nashville^  Tenn.^  June  11th,  1870. 
SYRUP  OF  SENEKA.— Correction. 
To  THE  Editor  American  Journal  of  Pharmacy  : 
Bear  Sir : — In  my  article  on  "  Syrup  Seneka,"  in  the  last 
number  (May)  of  this  Journal  I  discover  three  typographical 
errors,  one  of  which,  being  in  the  body  of  the  formula,  it  is  im- 
portant to  correct,  viz. :  at  page  229,  in  the  formula,  instead  of 
"  White  Sugar,  in  coarse  powder, /oi^r  troyounces,"  it  should 
read  White  Sugar,  in  coarse  powder,"  nine  troyounces  ;  and 
at  page  230,  line  85  from  top,  I  am  made  to  say  "  I  have  varied 
that  preference  in  this  instance,"  instead  of  "  I  have  waived  that 
preference  in  this  instance;"  also  at  page  231,  line  23  from  top, 
the  word  serves  is  inserted  instead  of  the  word  seems,  as  in  the 
manuscript.  Will  you,  therefore,  be  good  enough  to  give  this 
note  a  place  in  your  valuable,  and  usually  correct  and  reliable 
Journal,  and  oblige 
Yours  respectfully, 
J.  B.  Moore. 
June,  1870. 
ON  UNGUENTUM  HYDRARGYRI  OXIDI  RUBRI. 
By  Henry  A.  Bower. 
All  pharmaceutists,  I  presume,  have  been  annoyed  (and  that, 
too,  at  a  time  when  it  was  most  inconvenient  to  make  this  oint- 
ment up  fresh)  to  find  (when  wishing  to  use  it)  instead  of  a 
fine  red  color,  it  had  changed,  chameleon  like,  to  an  olive-green 
or  black. 
