534   PAPERS  READ  AT  THE  BRITISH  PHARM.  CONFERENCE. 
3.  In  the  dispensing  department,  or  other  suitable  place, 
there  should  be  a  repertorium  toxzcorum,  or  "  poison  cupboard," 
under  lock  and  key,  in  which  should  be  kept  all  the  concentrated 
and  virulent  poisons.  An  additional  protection  of  similar  cha- 
racter consists  in  securing  the  stopper  of  a  bottle  by  tying  over 
or  other  means. 
4.  It  is  advantageous  that  labels  on  shop  bottles  should  be 
visible  at  a  glance ;  the  words  being,  for  instance,  in  two  short 
lines,  on  a  square  label,  rather  than  in  one  line  on  a  long 
curved  label. 
5.  Where  practicable,  every  prescription  should  be  checked 
by  a  second  person  before  it  leaves  the  shop. 
6.  It  is  expedient  that  liniments,  lotions,  and  poisonous 
preparations  for  external  use,  should  be  sent  out  in  such  a  form 
as  to  be  easily  distinguished,  by  touch  as  well  as  sight,  from 
medicines  intended  for  internal  administration. 
7.  Every  specially  dangerous  substance  sold  by  the  chemist 
and  druggist  should,  in  addition  to  its  name,  be  distinctly  la- 
belled "Poison;"  except  in  the  case  of  medicines  dispensed 
from  a  prescription,  where  the  statement  of  the  use  or  dose 
may  be  considered  to  be  sufficient  precaution.  A  label  having 
the  word  "  Poison"  in  white  letters  on  a  black  ground  is  well 
adapted  for  the  above  purpose." 
ON  COMMERCIAL  PHOSPHORIC  ACID.     BY  R.  PARKINSON,  PH.D 
Twenty-eight  samples  had  been  examined  with  reference  to 
their  strength  and  freedom  from  impurity,  the  result  as  to 
strength  being  that  three  samples  came  up  to  the  British  Pharma- 
copoeia strength  ;  five  more  were  about  the  London  Pharmaco- 
poeia strength  ;  while  the  remainder  were  of  various  shades  of 
declension.  Phosphate  of  ammonia  was  present  in  six  samples, 
sulphuric  acid  in  one,  nitric  acid  only  traces  in  any.  The 
presence  of  ammonia  was  considered  evidence  that  the  samples 
containing  it  had  been  made  from  the  glacial  acid,  which,  com- 
mercially, is  made  by  heating  the  phosphate  of  ammonia,  the 
whole  of  the  ammonia  never  being  practically  got  rid  of.  One 
sample  of  German  glacial  contained  5  per  cent,  of  ammonia, 
which  is  equal  to  17 J  per  cent,  of  tribasic  phosphate  of  ammo- 
nia.   If  a  pure  glacial  acid  could  be  readily  obtained  commer- 
