AmDec.?Sarm-}   Revision  of  the  U.  S.  Pharmacopoeia.  601 
synthetic  oil  of  wintergreen  becomes  a  dangerous  precedent.  If 
synthetic  oil  of  wintergreen  is  to  be  officially  recognized,  why  not 
introduce  also  the  synthetic  essential  oils  of  almond  and  of  mustard  ? 
The  theoretical  necessity  for  a  more  accurate  classification  of  the 
pharmacopceial  preparations,  alone,  seems  to  have  decided  the  Com- 
mittee in  dividing  the  old  class  of  mixtures.  In  the  past,  pharma- 
cists have  felt  the  need  of  at  least  one  class  of  liquid  preparations, 
wherein  might  be  grouped  such  preparations  as  could  not  be  prop- 
erly classed  under  the  more  rigid  titles,  as  tinctures,  syrups,  liquors, 
etc.  The  title  "  mistura  "  was  deemed  sufficiently  elastic,  and  it  has 
always  conveyed  the  idea  of  a  heterogeneous  group  of  remedies. 
This  want  has  been  universal  and  in  the  British  Pharmacopoeia  and 
in  other  national  pharmacopoeias,  we  have  similar  groups  under  this 
title.  Under  the  new  classification  mixtures  are  more  nearly  related 
to  the  emulsions  than  heretofore.  It  remains  to  be  seen  if  the  new 
class  "Emulsa"  will  be  more  graciously  received  than  were  the 
abstracts  of  the  Pharmacopoeia  of  1880. 
Some  peculiar  changes  have  necessarily  resulted  in  the  formulas 
for  these  preparations.  In  brown  mixture,  syrup  and  mucilage  of 
acacia  are  now  directed  in  place  of  sugar  and  powdered  acacia* 
We  can  see  no  advantage  from  the  change. 
The  marked  changes  made  in  the  formula  for  Mistura  Rhei  et 
Sodse  are  such  that  we  cannot  approve.  To  make  this  formula  con- 
form strictly  to  the  newly  adopted  idea  of  a  mixture,  35  per  cent, 
by  volume  of  glycerin  is  introduced.  But  why  has  ipecac  been 
added  to  the. formula?  It  is  to  be  observed,  that  the  amount  of 
ipecac  is  one-fifth  that  of  the  rhubarb  ;  now  one  grain  of  ipecac  is 
quite  as  active  comparatively  as  the  five  grains  of  rhubarb,  and  this 
if  desirable  to  be  introduced  should  be  indicated  in  the  title. 
Oleate  of  Mercury  now  is  made  by  dissolving  20  parts  of  yellow 
oxide  of  mercury  in  80  parts  oleic  acid.  The  20  per  cent,  oleate 
will  be  found  more  permanent  than  the  10  per  cent,  of  1880.  The 
red  mercuric  oxide  finely  powdered  and  dried  answers  as  well  as  the 
yellow  oxide.  This  formula,  however,  still  leaves  a  decided  excess 
of  oleic  acid  not  in  combination.  The  true  oleate  prepared  by 
double  decomposition  (and  containing  but  a  very  small  amount  of 
free  oleic  acid  due  to  acidity  of  the  metallic  nitrate  solution  used) 
should  have  been  introduced.  Oleate  of  zinc  of  the  Pharmacopoeia 
is  likewise  a  solution  of  5  per  cent,  of  the  oxide  in  oleic  acid.  It 
