538  British  Phanmceutical  Conference,    {^'^  oct!,'''!^*'''^* 
that  the  activity  of  a  sample  of  insect  powder  could  be  readily  tested  by  trying 
it  directly  on  flies. 
Cassia  Tora. — The  results  of  a  "  Proximate  Analysis  of  the  Seeds  of  Cassia 
Tora^  by  Mr.  W,  Elborne,  formed  the  subject  of  the  next  paper.  These  seeds 
and  the  leaves  of  the  same  plant  are  used  in  India  as  a  remedy  for  ring-worm 
and  other  skin  diseases,  and  Dr.  Dymock  has  suggested  that  they  may  contain 
chrysophanic  acid.  In  Mr.  Elborne's  opinion  their  medicinal  activity  is  due  to 
a  substance  which  he  describes  as  resembling  emodin.  From  the  alcoholic  ex- 
tract he  states  that  he  obtained  a  glucoside,  which  he  calls  "  potential  emodin 
but  this  view  is  rather  conjectural  than  the  result  of  satisfactory  experiment, 
and,  as  pointed  out  by  Mr.  Naylor,  the  subject  requires  further  investiga- 
tion. 
The  Solubility  of  Citrate  of  Caffeine  was  the  subject  of  a  paper  read  by  Mr. 
Gerrard,  in  which  he  criticised  the  official  description  of  the  drug  in  the  Brit- 
ish Pharmacopoeia.  Having  endeavored  to  make  a  ten  per  cent,  solution  for 
convenience  in  dispensing,  he  found  that  out  of  five  samples  purchased  not  one 
was  sufficiently  soluble,  and  none  of  them  corresponded  to  the  official  state- 
ment that  the  preparation  should  form  a  syrupy  solution  with  a  little  water. 
Using  a  sample  prepared  by  himself  Mr.  Gerrard  met  with  the  same  difficulty. 
His  experiments  led  him  to  the  conclusion  that  citrate  of  caffeine  has  a  mean 
solubility  of  about  1  in  30.  He  is  therefore  of  opinion  that  the  statement  in 
the  British  Pharmacopoeia  is  a  mistake  that  has  also  found  its  way  into  other 
works. 
Caffeine. — In  the  succeeding  paper,  by  Mr.  J.  Moss,  an  instance  was  given  in 
which  an  article  represented  to  be  "  Citrate  of  Caffeine,  Old  P.B.,"  consisted  simply 
of  caffeine,  without  a  trace  of  citric  acid.  No  explanation  could  be  obtained  of 
the  designation,  and  evidently  in  dispensing  such  an  article  as  citrate  of  caf- 
feine, as  nearly  as  possible  twice  the  dose  of  caffeine  intended  would  be  given.. 
Laboratory  Notes,  by  Mr.  R.  Wright.  The  first  note  was  on  Acetum  Ipecacu- 
anhse,  and  described,  apparently,  the  work  that  led  up  to  the  formula  adopted 
by  the  Unofficial  Formulary  Committee.  The  second  was  on  Liquid  Extract  of 
Cascara.  In  the  endeavor  to  prepare  a  tasteless  extract,  it  was  found  that  when 
lime  was  used  a  pale  colored  extract  was  produced  apjiarently  destitute  of  any 
laxative  property.  But  when  a  mixture  of  the  bark  with  magnesia  was  ex- 
tracted with  dilute  alcohol,  the  preparation  obtained  was  free  from  bitterness,, 
and  appeared  to  act  as  powerfully  as  the  bitter  extract.  The  next  note  was  on 
Syrupus  Ferri  Phosphatis,  and  described  a  process  for  the  preparation  of  an  im- 
proved syrup  containing  a  smaller  proportion  of  acid  and  at  the  same  time  ad- 
mitting of  dilution  without  deposit  of  phosphate  For  that  purpose,  the  author 
recommends  to  dissolve  360  grains  of  iron  wire  in  6  fluidounces  of  syrupy  phos- 
phoric acid,  sp.  gr.  I'SO,  and  9  ounces  of  distilled  water,  filtering  the  solution 
into  72  fluidounces  of  simple  syrup  and  adding  water  to  make  up  96  fluidounces. 
The  last  note,  on  Unguentum  Hydrargyri  Oxidi  Flava,  described  the  results  of 
experiments  made  to  supply  the  want  of  an  authoritative  formula.  The  B.  P. 
formula  for  Unguentum  Hydrargyri  Oxidi  Rubri  did  not  give  the  author  a  sat- 
isfactory product.  By  melting  yellow  wax  with  soft  paraffin  in  the  proportion 
1  to  from  7  to  16  according  to  the  prevailing  temperature,  a  satisfactory  oint- 
ment may  be  obtained.  The  discussion  following  the  reading  of  this  paper 
turned  principally  upon  the  efficacy  of  the  "tasteless  "  cascara  extract,  and  di&- 
