532  British  Pharmaceutical  Conference.        { "^""oct^iSr'"'' 
of  iron  by  this  metJiod.  The  examination  of  twelve  samples  of  commercial 
syrup  of  iodide  of  iron  sliowed  that  the  amount  of  ferrous  iodide  varied 
from  2|  grains  to  rather  more  thaii  4  grains  in  a  fluidrachm.  The  cause  of 
the  deficiency  in  some  of  these  instances  the  authors  propose  to  deal  with 
on  a  future  occasion.  Mr.  M.  W.  AVilliams  suggested  that  a  simple  method 
of  determining  the  amount  of  iodides  in  solution  might  be  devised  on  the 
basis  of  the  dark  coloration  produced  on  the  addition  of  bichloride  of  plati- 
num, carrying  this  out  after  the  manner  of  the  Nessler  test  for  ammonia. 
Mr.  Merck,  of  Darmstadt,  contributed  a  paper  on  the  Proximate  Princi- 
ples of  Henbane^  in  which,  at  the  request  of  the  President,  he  stated  the 
])resent  condition  of  our  knowledge  of  them.  The  principal  facts  con- 
tained in  this  paper  have  already  been  stated  in  the  "Month"  ("Phar. 
Jour."  [3],  vol.  xi,  p.  351,  and  vol.  xii,  p.  179). 
In  the  paper  by  Mr.  Benger  on  the  Pharmacopceia  Test  for  Pepsin  vari- 
ous suggestions  were  offered  for  removing  tlie  defects  of  that  test.  In  order 
to  remedy  its  tediousness,  Mr.  Benger  recommended  that  the  temperature 
should  be  raised  to  130°F.,  at  whieli  point,  as  already  observed  by  M.  Petit, 
the  action  of  pepsin  is  very  much  more  rapid  than  at  98°F.  He  also 
recommended  that  the  coagulated  white  of  egg  should  be  used  in  a  state  of 
finer  and  more  definite  subdivision  than  that  described  as  "  thin  shavings." 
For  that  purpose  he  recommends  that,  according  to  Mr.  DowdeswelFs 
l)lan,  the  white  of  egg  should  be  j^assed  through  wire  gauze  made  of  No.  32 
(Birmingham  wire-gauge)  coi3per  wire  and  containing  36  meshes  to  the 
linear  incli.  The  acid  he  uses  has  a  strength  of  about  0*3  per  cent,  of  HCl. 
Operating  in  this  way,  and  observing  certain  minute  details  2  grains  of  an 
active  pepsin  should  almost  entirely  dissolve  100  grains  of  white  of  egg  in 
twenty  minutes,  instead  of  tlie  four  hours  required  by  the  Pharmacopoeia 
test.  Prol^essor  Attfield  pointed  out  that  the  temperature  recommended 
was  much  higher  than  that  of  the  stomach,  and  Dr.  Symes  suggested  that 
the  doubt  tlius  raised  as  to  the  test  should  be  settled  by  making  compara- 
tive tests  at  the  two  temj^eratures.  Mr.  Benger  stated  that  he  had  already 
done  this  and  found  that  the  pepsins  that  were  most  active  at  the  higher 
temperature  were  also  the  most  active  at  the  lower.  Mr.  M.  W.  Williams 
remarked  that  the  acid  of  the  stomach  was  not  generally  admitted  to  be 
hydrochloric  acid,  but  however  that  may  be,  it  is  worth  noting  that  M. 
Petit  has  shown  ("  Amer.  Journ.  Pharm.,"  1880,  p.  155)  that  hydrochloric 
acid  is  the  most  favorable  to  the  action  of  pepsin. 
Professor  Attfield's  paper  on  "  Copying  Ink  for  Peadily  Transcribing 
Letters  Without  a,  Copying  Press,^^  described  his  experience  of  the  use  of 
ink  made  by  evaporating  any  ordinary  ink  to  rather  more  than  one-half, 
and  then  making  up  the  original  volume  with  glycerine.  A  firm  of  man- 
ufacturers had  entertained  his  suggestion  to  use  such  an  ink  as  this  and 
went  to  the  exi:)ense  of  provisionally  patenting  it,  in  the  hope  of  render- 
ing it  an  ordinary  commercial  article,  but  the  project  has  long  been  aban- 
doned and  found  sufficiently  impracticable  to  admit  of  its  publication.  Pro- 
fessor Attfield  has  found  the  ink  really  valuable  to  himself  and  thinks  it 
may  also  prove  serviceable  t()  others. 
The  note  on  Tests  for  Nitrates  in  Potable  Water  ^  by  Mr.  Ekin,  described 
