AFebSSvTi9awm"}         Bismuth  Salicylate,  Basic.  67 
mittee  of  Revision  even  deemed  it  undesirable  to  give  a  formula  for 
such  old  and  well-established  bismuth  compounds  as  bismuth  subni- 
trate and  subcarbonate.  Nor  did  it  prescribe  any  limits  as  to  how 
much  or  how  little  bismuth  these  articles  should  contain.  And  in 
view  of  some  recent  investigations,  this  course  has  been  a  most 
commendable  one.  According  to  the  commonly  accepted  formula, 
bismuth  subnitrate  should  leave  on  ignition  76413  per  cent,  of 
Bi203,  but  C.  O.  Curtman1  found  it  to  vary  from  8riO  to  85-00 
percent.,  and  the  writer2  found  it  to  contain  from  8roo  to  83-26  per 
cent. ;  and  the  per  cent,  of  nitric  acid  varied  very  markedly.  If, 
therefore,  the  compound  BiON03,H20  exists,  it  is  so  unstable  and 
difficult  to  prepare  that  not  a  single  manufacturer  is  able  to  supply 
it.    The  same  is  true  of  the  subcarbonate  of  bismuth. 
The  argument  has  been  advanced  that  a  variation  in  the  com- 
position of  the  basic  salicylate  causes  a  variation  in  therapeutic 
effect.  This  has  probably  resulted  from  a  confusion  between  the 
so-called  normal  and  the  basic  articles.  For  such  an  argument, 
considering  the  quality  of  bismuth  subsalicylate  now  supplied,  in 
the  writer's  opinion,  is  hardly  as  tenable  as  it  would  be  with  either 
the  subnitrate  or  subcarbonate. 
Basic  bismuth  salicylate  is  slowly  decomposed  by  water,  alcohol, 
glycerin,  syrups,  etc.  An  aqueous  solution  of  sugar  causes  more 
rapid  decomposition  than  plain  water.  This  is  probably  due  to  the 
fact  that  salicylic  acid  is  more  readily  soluble  in  a  saccharine  men- 
struum than  in  water.  It  would,  therefore,  appear  that  this  bismuth 
salt  must  be  considered  as  a  molecular  compound  of  bismuth  oxide 
and  salicylic  acid,  rather  than  a  true  salt. 
From  the  above  considerations  it  would  not  be  surprising  to  find 
that  the  commercial  article  varied  considerably,  and  in  order  to 
ascertain  to  what  extent  this  is  true,  samples  were  secured  from 
various  sources  and  examined  with  the  following  results  : 
1  1896,  Phartn.  Era,  15,  43. 
2 1896,  Am.  Jour.  Pharm.,  68,  422. 
