350 
CARBOLIC  ACID  PLASTER. 
rations,  would  avoid  some  of  the  objections  inherent  to  those 
referred  to,  prominent  among  which  I  might  mention  their  odor. 
For  this  purpose  I  would  suggest  the  carbolate  of  glycerin, 
which,  with  isinglass,  forms  an  even,  homogenous  mixture,  capable 
of  being  spread  on  cloth  or  paper  in  the  same  manner  in  which 
ordinary  courtplaster  is  prepared,  while  it  is  easily  miscible 
with  any  of  the  odorous  principles  with  which  nature  abounds, 
and  which  sufiSce  to  mask  the  inherent  odor  of  the  acid.  The 
presence  of  glycerin  prevents  the  complete  drying  of  the  isin- 
glass, and  preserves  it  in  that  elastic,  india-rubber  like  state, 
which  prevents  the  escape  of  any  carbolic  acid. 
If,  as  in  courtplaster,  the  tissue  is  coated  twice,  the  top  layer 
will  certainly  preserve  the  carbolic  acid  of  the  lower  stratum  as 
securely  as  a  well-stoppored  bottle  would,  so  that  the  plaster  is 
not  likely  to  suffer  a  diminution  of  its  good  qualities  by  age. 
But  as  both  coats  are  extremely  thin,  the  moistening  of  the 
plaster  on  its  application,  conjointly  with  the  elevated  tempera- 
ture of  the  skin  applied  to,  removes  at  once  every  impediment 
to  the  absorption  of  the  carbolic  acid  by  the  cuticle  beneath  it. 
The  presence  of  carbolic  acid  would  not  preclude  the  use  of 
arnica  in  such  a  plaster,  if  desirable,  although  the  modern  taste 
for  simplifying  the  existing  combinations  of  remedial  agents 
would  hardly  recommend  such  a  mixture,  the  efficacy  of  which 
would  depend  npon  the  presence  of  carbolic  acid. 
This  rebuke  of  unnecessary  complication  cannot  be  urged 
against  the  presence  of  glycerin,  as  this  substance  aids  greatly 
in  producing  a  homogeneous  mixture  of  the  acid,  isinglass 
and  oil,  used  for  the  concealment  of  the  odor  of  the  acid,  while 
it  also  produces  and  preserves  the  elasticity  of  the  plaster. 
The  side  of  the  tissue  not  coated  with  the  carbolate  may,  like 
that  of  courtplaster,  be  rendered  waterproof,  for  which  purpose 
a  solution  of  india-rubber,  paraffine  or  of  collodion  would  be  most 
suitable. 
Upon  being  rendered  waterproof,  paper,  as  suggested  above, 
may  in  many  cases  be  substituted  for  silk  or  other  tissue,  as  the 
waterproof  coating  on  one  side,  as  also  the  two  of  isinglass  on 
the  other  add  to  it  considerable  cohesive  strength. — The  Phar- 
macist, Chicago  J  March,  1869. 
