5 1 8  Revision  of  the  U.  S.  Pharmacopoeia.  {XmN™'im&im' 
mixture.  While  "  mistura  "  is  hardly  an  appropriate  name  for  a 
clear  liquid  preparation,  the  term  liquor  strikes  us  very  strangely  for 
a  preparation  containing  over  twenty  per  cent,  of  flavoring  and 
s  weetening  material.  Would  not  "  Elixir  "  have  been  a  more  appro- 
priate name  ? 
It  is  to  be  observed  that  Acetum  Opii  and  Acetum  Scillae  are  now 
made  by  maceration  instead  of  percolation,  the  strength  remaining 
about  the  same  as  in  1880. 
There  are  some  changes  in  the  acids  of  the  Pharmacopoeia, 
requiring  notice.  Volumetric  solution  of  potassic  hydrate  with 
phenolphthalein  as  an  indicator,  is  generally  adopted  for  determining 
strength.  Acid,  acetic,  still  remains  the  36  per  cent,  acid  and  the 
glacial  acid  99  per  cent.  It  would  have  been  well  to  have  changed 
the  former  to  the  60  per  cent,  acid  now  being  manufactured  exten- 
sively. 
It  is  to  be  regretted  that  under  the  title  of  benzoic  acid  both  the 
natural  and  the  synthetic  acids  are  recognized  and  that  in  the  tests 
for  identification  the  latter  seems  to  be  given  the  preference.  In 
the  past,  we  have  been  taught  to  discriminate  against  the  artificial 
acids  and  tests  were  proposed  to  detect  such  substitutes  or  adulter- 
ants of  the  natural.  Those  who  have  administered  both,  and  ben- 
zoates  made  from  both,  distinguish  a  practical  difference.  The 
administering  of  the  synthetic  is  generally  followed  by  a  disagree- 
able taste,  very  persistent  and  frequently  producing  nausea.  This 
effect  is  most  likely  due  to  toluol  derivatives  remaining  as  impuri- 
ties, but  is  nevertheless  recognized  and  physicians  are  careful,  in 
many  instances,  to  specify  "  natural."  Tinctura  Opii  Camphorata, 
should  be  stated  as  a  benzoic  acid  preparation ;  Phenol,  should  be 
the  title,  with  carbolic  acid  as  a  synonym.  A  volumetric  method 
for  determining  the  amount  of  absolute  phenol  present,  and  depend- 
ing on  the  tribrom-phenol  reaction,  has  been  adopted.  Likewise 
Chromic  trioxide  and  chromic  anhydride  are  given  as  synonyms  for 
Acidum  Chromicum  ;  the  former  would  be  the  correct  title. 
Diluted  Hydrocyanic  Acid  is  again  a  two  per  cent,  solution  in 
water  only.  The  acid  as  distilled  being  condensed  in  a  receiver 
containing  distilled  water,  not  diluted  alcohol,  as  in  the  pharma- 
copceial  process  of  1880;  and  the  distillation  is  stopped  when  the 
volume  of  liquid  in  the  retort  is  reduced  to  one-half.  The  retention 
of  the  formula  for  making  this  acid  extemporaneously,  is  surely 
unnecessary. 
