AmjuJneUr'Jih9arm'  )       Standardising  Disinfectants.  395 
clearly  that  the  question  of  the  manufacture  of  pharmaceutical 
products  is  not  so  simple  or  so  attractive  as  is  often  believed.  New- 
comers, he  says,  will  find  themselves  very  quickly  in  the  presence  of 
difficult  situations,  and  bitter  competition  awaits  them,  both  at  home 
and  abroad.  It  is  imperative,  he  concludes,  that  the  laws  now  under 
consideration  regarding  patents  and  trade-marks  should  ensure  to 
these  manufacturers  sufficient  guarantees  for  their  enterprise  with- 
out harm  to  the  general  interest.  It  is  also  necessary  that  they 
should  be  kept  well  informed  of  everything  that  is  being  done  at 
home  and  abroad,  and  that  official  science  should  support  them 
openly  and  without  expectation  of  immediate  reward.  Finally,  as 
the  pharmaceutical  industry,  like  other  industries,  has  given  the 
state  all  possible  assistance  during  the  war,  it  is  the  duty  of  the 
state  to  protect  it  now. 
STANDARDIZING  DISINFECTANTS.1 
Dr.  Samuel  Rideal  communicates  to  the  British  Medical  Journal 
the  following  details  of  the  standard  bacteriological  test  (Rideal- 
Walker  Method)  adopted  by  the  members  of  the  British  Disin- 
fectant Manufacturers'  Association :  Well  shake  the  bottle  or  other 
vessel  containing  the  disinfectant  before  proceeding  to  make  the 
dilution.  Make  a  1  per  cent,  stock  emulsion  (5  Cc.  of  disinfectant 
added  to  495  Cc.  of  boiled  distilled  water  of  150  C.  to  180  C). 
From  this  stock  emulsion  prepare  required  dilutions  in  boiled  dis- 
tilled water,  taking  care  that  pipettes  used  for  preparing  stock  emul- 
sion as  well  as  dilutions  are,  after  emptying,  always  well  washed 
out  with  and  into  the  diluent,  and  that  all  dilutions,  including  stock 
emulsion,  are  well  shaken  before  use.  To  5  Cc.  of  a  particular  dilu- 
tion add  0.2  Cc.  (5  drops)  of  a  broth  culture  of  B.  tyhposus  grown 
for  twenty-four  hours  at  370  C.  Shake  immediately  after  medica- 
tion. Keep  medicated  tubes  at  temperature  of  io°  C.  to  180  C.  and 
take  subcultures  into  5  Cc.  broth  every  two  and  a  half  minutes  up 
to  ten  minutes.  Incubate  for  a  least  forty-eight  hours  at  370  C. 
Rideal  and  Walker,  (/.  5.  L,  October,  1903,  p.  424),  use  as  stock 
organism  B.  typhosus  from  a  single  colony  on  an  agar  plate  culture 
that  has  been  grown  at  2 1-22 0  C.  from  two  to  seven  days  and 
removed  by  weekly  transference  for  several  uninterrupted  genera- 
1  Reprinted  from  The  Chemist  and  Druggist,  April,  1919. 
