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POLITICAL  ECONOMY

pieces  of  money  are  not  wanted  to  keep
but  to  pass  on.  However,  to  this  objection
it  may  be  retorted  that  all  the  things  that
we  buy  are  not  goods  which  we  retain  permanently ­
  or  for  long.  Many  of  the  things
really  sought  when  we  make  purchases  are  the
services  associated  with  objects  which  are
passed  on  to  perform  the  same  services  for
other  people  when  so  much  of  each  service
as  we  require  has  been  used  up  by  ourselves.
When  we  habitually  have  recourse  to  railway
trains,  we  do  not  and  cannot  buy  them  for
our  private  use,  but  we  take  on  each  occasion
from  a  public  conveyance  just  as  much  of
the  service  of  transportation  as  we  require.
It  is  not  only  money  that  circulates,  as  it  is
put  :  railway  trains  and  ships,  and  telegraph
boys  and  hired  waiters  circulate  also,  and  in
circulating  do  work  for  which  the  community
is  ready  to  pay  a  price
Let  us  consider  next  how  the  prices  of
these  things  that  circulate  are  settled.  In
dealing,  say,  with  the  price  of  cabs  in  a
community,  we  have  to  analyse  the  forces  of
demand  and  supply.  Certain  utilities  consisting ­
  in  rides  in  cabs  are  demanded,  and  the
supply  with  which  we  are  primarily  concerned
is  the  supply  not  of  cabs  but  of  the  services
performed  by  cabs.  These  services,  however,