Am.  Jour.  Pharm.) 
February,  1895.  J 
Pharmaceutical  Notes. 
87 
The  same  reaction  may  take  place  in  other  instances,  perhaps 
less  frequently,  yet  being  at  times  of  importance  at  the  dispensing 
counter,  occasionally  requiring  some  reflection  before  unlooked-for 
phenomena  are  satisfactorily  explained. 
Some  weeks  ago  a  mixture  consisting  of  aqueous  tincture  of  rhu- 
barb and  glycerin  was  found  to  explode  when  dispensed  in  a  well- 
filled  bottle. 
When  this  mixture  was  prepared  in  an  open  vessel,  distinct 
effervescence  could  be  observed  on  standing. 
Tinctura  rhei  aquosa,  a  preparation  frequently  prescribed  by 
German  practitioners,  contains,  besides  the  active  vegetable  ingre- 
dient, borax  and  potassium  carbonate. 
The  glycerin  decomposes  the  sodium  borate,  with  liberation  of 
free  boric  acid,  and  the  latter  is  again  neutralized  by  the  potassium 
carbonate  present  with  evolution  of  C02. 
The  expansion  of  this  gas  renders  the  bottle  holding  this  mix- 
ture liable  to  fracture. 
BORAX  IN  UNGUENTUM  AQU^E  ROS££. 
Several  objections  have  been  made  against  the  addition  of  borax 
to  the  cold  cream  of  the  new  Pharmacopoeia. 
The  action  of  the  borax  upon  salts  of  mercury  and  the  alkaloids 
appears  to  be  the  chief  objection. 
The  addition  of  glycerin  to  cold  cream,  as  sometimes  ordered 
extemporaneously  in  prescriptions,  will  also  decompose  the  borax 
in  the  manner  mentioned. 
Borax  appears  to  possess  some  saponifying  action  upon  the  fatty 
ingredients,  and  if  glycerin  is  subsequently  added,  boric  acid  is 
liberated,  changing  the  reaction  of  the  ointment  from  alkaline  to 
acid. 
It  would  be  interesting  to  know  whether  this  would  produce  an 
impairment  of  the  preparation  as  to  its  medicinal  value. 
GLYCERIN  AND  SOME  BAY  RUM  SAMPLES. 
The  pharmacopoeial  bay  rum  formula  is  not  satisfactory  to  many 
pharmacists  on  account  of  the  almost  colorless  appearance  of  the 
product. 
In  their  efforts  to  cater  to  the  popular  taste,  they  prefer  to  have 
the  preparation  of  a  bright  yellow,  or  even  yellowish-brown  color. 
