^™0cr'ir83^™'}         Commercial  Iodide  of  Potassmm.  505 
None  of  the  pharmacopoeial  deficiencies  found  are  very  grave  in 
character.  In  the  most  important  medicinal  requirement,  the  absence 
ofiodate  or  of  more  than  traces  of  it,  one  of  the  samples  is  just  upon 
the  U.  S.  Ph.  test-limit,  and  the  others  are  standard  (though  No.  1 
does  not  stand  very  strong  in  this  test).  In  the  limit  of  alkali,  a  require- 
ment of  less  medicinal  than  pharmaceutical  importance,  the  pharma- 
copoeias have  been  very  lax.  Two  samples  are  below  the  exact  stand- 
ard and  one  just  upon  it.  The  limit  of  chloidde  and  bromide  is  one 
more  difficult  for  the  manufacturer  to  control,  and  a  margin  beyond 
this  limit  is  less  injurious.  Here  none  of  the  samples  quite  meet  the 
U.  S.  Ph.  standard.  In  the  case  of  numbers  1  and  2,  the  presence  of 
chloride,  though  probably  not  over  1  to  IJ  per  cent,  of  the  salt,  had 
doubtless  been  the  cause  of  the  larger  access  of  moisture  found  in  test 
(7),  and  had  thereby  diminished  the  chemical  stability  of  the  salt.  In 
numbers  3,  4,  and  5,  the  slight  proportions  of  chloride  and  bromide 
beyond  the  limit,  may  well  be  passed  as  not  important.  Most  of  the 
^mples  were  found,  also,  with  too  much  sulphate.  This  completes  the 
list  of  the  pharmacopoeial  deficiencies. 
It  is  certainly  desirable  that  our  medicinal  iodide  of  potassium  should 
be  so  far  improved  as  to  be  made  uniform  with  its  best  portions,  these 
being  already  nearly  or  quite  conformable  to  the  requirements  of  the 
Pharmacopoeia.  Especially  in  the  important  features  of  absence  of 
iodate,  and  close  limit  of  alkali,  the  standard  (fortunately  fixed  by  the 
simplest  possible  of  tests)  may  well  be  looked  after  by  purchasers. 
Indeed  the  manufacturers  need  the  encouragement  of  an  intelligent 
appreciation  to  enable  them  to  eliminate  deficiencies  from  their  pro- 
ducts. It  is  asking  much  of  the  honor  and  sagacity  of  men  that  they 
should  devote  care  and  capital  to  provide  grades  of  purity  never  to  be 
recognized  by  one  in  a  hundred  of  the  consumers.  It  is  leaving  a 
good  deal  to  the  manufacturers,  that  it  should  ever  be  their  part  to 
stimulate  a  demand  for  sounder  qualities  of  their  products. 
Medicinal  chemicals  may  be  tested  and  valued  with  more  readiness 
and  certainty  than  most  other  articles  of  commerce.  The  wardens  of 
their  consumption  are  the  dispensing  pharmacists.  A  demand  for 
strictly  pharmacopoeial  chemicals,  an  intelligent,  healthful,  steady 
demand,  if  it  comes  at  all,  must  come  through  the  avenues  of  daily 
trade  from  dispensing  pharmacists  who  habitually  apply  their  own 
tests,  value  their  own  purchases,  verify  pharmacopoeial  standards,  and 
know  their  own  best  business.    Such  a  good  demand  will  cause  the 
