imPtSrSra"(    British  Pharmaceutical  Conference.  447 
determinations  of  the  amount  of  iodine  or  pure  mercurous  iodide 
contained  in  specimens  of  the  compound  made  in  different  ways. 
Those  results  indicate  that  precipitated  mercurous  iodide  is  quite 
uniform  in  composition  and  also  sufficiently  stable  when  properly 
protected. 
Copaiba  of  British  Guiana. 
By  E.  W.  Bell. 
As  the  result  of  an  examination  of  a  specimen  of  British  Guiana 
copaiba,  the  author  finds  it  to  respond  to  all  the  characters  and  tests 
of  the  British  Pharmacopoeia,  except  as  regards  the  optical  rotation 
of  the  volatile  oil,  and,  in  that  respect,  the  B.P.  monograph  is  sup- 
posed to  be  in  error.  The  official  tests  for  copaiba  are  criticised 
generally,  and  it  is  suggested  that  there  should  be  a  definite  method 
for  obtaining  the  percentage  of  oil,  preferably  by  evaporation  at 
about  100°  C;  it  is  also  suggested  that  the  rotation  figures  for  the 
volatile  oil  should  be  lowered,  that  titration  of  the  oleoresin  be 
introduced  and  a  resin  factor  added. 
Assay  Apparatus  for  Chlorine  or  Nitrogen. 
By  J.  F.  Tocher. 
A  new  form  of  apparatus  for  the  determination  of  chlorine  or 
nitrogen  is  described  by  the  author.  The  advantages  claimed  for  it 
are  that  loss  of  chlorine  or  ammonia  is  entirely  prevented,  whilst  the 
condensing  apparatus  is  much  simplified,  and  the  fluid  and  washings 
can  be  readily  run  off  for  titration,  the  apparatus  then  being  ready 
for  another  operation.  In  nitrogen  determinations  the  flask  can  be 
used  with  advantage  in  decomposing  the  nitrogenous  substance 
prior  to  distillation  and  prevents  possible  loss  in  transference. 
Nux  Vomica  Assay. 
By  E.  H.  Farr  and  R.  Wright. 
The  authors  point  out  that  the  volume  of  liquid  taken  should  not 
exceed  5  c.c.  of  liquid  extract,  or  30  c.c.  of  tincture,  and  that  200  c.c. 
of  wash  water  at  a  stated  temperature  (380  C.)  should  be  employed, 
a  correction  being  made  for  the  strychnine  dissolved. 
