86 
Pliarmacentical  Notes. 
/Am.  Jour.  Pharm 
1    February,  1895. 
and  if  the  latter  is  not  free  from  iron,  a  red  coloration  is  sure  to 
take  place. 
This  was  observed  with  a  perfectly  colorless  sample  of  the  acid. 
Salicylic  acid,  in  particular  its  sodium  salt,  is  a  compound  which 
is  readily  affected  in  this  manner.  The  fact  that  a  perfectly  color- 
less aqueous  solution  of  this  salt,  when  mixed  with  glycerin,  turned 
to  a  reddish  violet  color,  first  drew  the  writer's  attention  to  the 
presence  of  the  metal  in  the  latter. 
Similar  effects  can  also  be  observed  with  other  aromatic  com- 
pounds, especially  with  a  number  of  the  new  remedies,  such  as 
antipyrine,  salipyrine,  etc. 
The  following  prescription  was  the  subject  of  a  controversy 
between  a  physician  and  a  pharmacist : 
Tinct.  Guaiaci, 
Glycerini,    aa  %  i 
Aquae  Rosas,     %  ii. 
When  this  mixture  was  dispensed,  it  was  found  to  acquire  a  blue 
color  on  standing. 
This  took  place  either  with  or  without  the  presence  of  gum  arabic, 
thereby  proving  the  same  not  to  be  a  factor  in  the  change. 
An  examination  of  the  rose  water  failed  to  find  any  oxidizing 
agents,  but  an  examination  of  the  glycerin  revealed  the  presence  of 
iron. 
The  same  prescription  was  sent  to  several  reputable  pharmacists 
to  be  compounded  for  the  sake  of  comparison,  almost  invariably 
showing  the  same  result,  with  only  one  exception,  indicating  the 
presence  of  iron  in  glycerin  to  be  quite  general. 
Other  color  reactions,  produced  by  this  impurity,  may  also  take 
place,  but  a  consideration  of  analytical  principles  will  enable  the 
well-informed  pharmacist  to  satisfactorily  explain  the  cause  of  any 
such  changes. 
THE  ADDITION  OF  GLYCERIN  TO  BORAX  PREPARATIONS. 
The  fact  that  glycerin,  when  added  to  aqueous  solutions  of  borax 
decomposes  the  latter  with  formation  of  free  boric  acid  is  well 
known. 
The  frequently  asked  query  :  What  is  the  cause  of  the  effervescence 
in  preparing  Dobell's  solution?  finds  its  explanation  in  this  manner, 
also  the  pharmacopceial  identity  test  for  glycerin. 
