The  sedatives  that  I  have  found   most  generally  useful  to  allay  pal-
pitation and  inordinate  action  of  the  heart,  are  camphor,  hydrocyanic
acid,  hyoscyamus,  belladonna,  asafoetida,  ether,  and  opium.     The
last  is  generally  the  most  powerful,  but  its  effect  on  the   circulation
being  irregular,   it  is  apt  to  disorder  the  secretions,  and  occasion
subsequent  congestions,  which   may  continue  to  disturb  the  heart's
action.     By  combining  it  with  mercurial  medicines,  and  ipecacuanha
or  colchicum,  and   following  its  operation  by  an  aperient,  these  bad
consequences  may  often  be  prevented.     I  have  found  digitalis  to  ex-
ercise far  less  control  over  the  heart  when  primarily  excited   than
when  its  action  is  quickened  by  disease  of  other  organs;  and  as  it
appears  to  me,  when  it  does  act,  to  diminish  the  power  of  the  heart
as  well   as  its   irritability,  I  think  that  its  use  should  be  confined  to
those   cases  of  perpetually  increased   action,  in  which  a  hurtful  ex-
cess of  strength  is  manifest  in  the  pulse,  as   well  as  a  frequency  of
the  contractions.     Of  the  other  remedies  named,  I  have  found  all
occasionally  beneficial,  either  singly  or  in  combination  ;  but  I  think
that  they  are  more  so  when   given  in  a  few  large  doses,  to  break  as
soon  and  as  completely  as  possible  the  habit  of  morbid  action,  which,
when  established,  is  much  more  difficult  to  remove.     Hydrocyanic
acid  must  be  excepted  from  this  rule,  for  in  large  doses  it  acts  like


336  WILLIAMS  ON  THE  CHEST.
