t™ptembr4r!hiS""}         United  States  Pharmacopoeia.  433 
should  be  directed  to  be  used  that  had  been  previously  titrated 
against  each  other,  using  the  same  indicator  as  used  in  the  final 
titration  of  the  alkaloid,  thus  greatly  reducing  the  danger  of 
experimental  error. 
CHEMICALS. 
Cerium  Oxalate. — This  title  is  officially  and  now  legally  applied 
to  a  varying  "  mixture  of  the  oxalates  of  cerium,  didymium,  and 
lanthanum  and  other  rare  earths  of  this  group."  The  title  should 
be  modified  so  as  to  show  that  it  is  the  so-called  "  medicinal,  com- 
mercial, or  admixed  "  salts  that  is  official  and  not  the  pure,  definite 
salt. 
SafroL — This  is  officially  defined  as  "  the  methyl  ether  of 
allylpyrocatechol,  found  in  oil  of  sassafras,  camphor  oil,  and  other 
volatile  oils,  purified,  if  necessary,  by  repeated  chilling  and  crystal- 
lization." This  definition  leaves  out  an  important  statement, 
namely,  the  preparation  which  must  precede  the  purification.  In 
the  official  statement  the  following  should  be  added  before  the  word 
purified,  "  separated  by  fractional  distillation." 
Scopolamine  Hydrobromide. — This  is  defined  as  "  obtained  from 
plants  of  the  Solanacece  and  chemically  identical  with  Hyoscine 
hydrobromide."  No  tests  are  given,  and  if  hyoscine  and  scopola- 
mine are  identical  and  the  article  is  commonly  sold  under  either 
name,  then  the  U.S. P.  should  certainly  eliminate  one  title  and  make 
in  the  text  a  statement  of  the  identity  of  these  two  commercial 
alkaloidal  salts.  The  writer  would  recommend  that  the  official  title 
retained  be  Scopolaminae  Hydrobromidum  as  indicating  the  most 
common  source,  Scopola,  and  being  a  distinctive  name,  serving  to 
prevent  confusion  and  possibly  dangerous  error  from  the  close  simi- 
larity of  hyoscine  with  hyoscyamine. 
Thymol  Iodide.- — The  writer  will  once  more  direct  attention  to  the 
act  that  the  official  definition  as  "  dithymol  diiodide  "  is  incorrect 
despite  all  the  text-book  theories.  The  iodides  of  thymol  supplied 
and  used  are  mixtures  of  several  iodine  substitution  compounds  of 
thymol,  and  a  thorough  research  to  settle  their  composition  should 
authoritatively  be  undertaken  before  the  next  revision. 
PHARMACEUTICAL  PREPARATIONS. 
Ceratnm  Cantharidis. — The  official  formula  directs  that  the  pow- 
dered cantharides  be  macerated  with  150  grammes  liquid  petrolatum 
