THE  CURRENCY  i53
Introduced  under  the  treaty  of  Nanking  (1842),  the
lapse  of  sixty  years  has  not  sufficed  to  create  modifications
in  this  standard,  which,  moreover,  is  current  for  revenue
purposes  in  all  the  ports  open  to  foreign  trade.  Even  with
this  currency,  however,  this  immutability  has  to  be  taken
with  some  reservation.  It  seldom  happens  that  the  merchant ­
  has  at  hand  to  pay  his  duties  the  fine  silver  (1,000)
which  is,  theoretically,  the  standard  for  all  payments  to
government  ;  and  tendering  other  silver,  commonly  the
ordinary  trade  silver  of  the  place,  the  rate  at  which  it  shall
be  accepted  becomes  a  matter  of  arrangement  with  the
banker  ;  the  latter,  having  to  account  to  the  government
for  a  certain  weight  of  silver  1,000  fine,  will  be  careful  to
receive  an  amount  in  other  silver  fully  sufficient  in  value
to  cover  his  liability.  Another  element  of  variation,  even
in  this  currency,  is  the  difference  between  the  receiving
and  paying  rates  in  force  in  all  government  treasuries,
all  banks,  and  with  those  merchants  of  sufficiently  strong
standing  to  make  their  own  counting-house  rules  ;  this
difference,  usually  between  a  quarter  and  a  half  of  one
per  cent.,  is  made  not  by  charging  a  commission,  but  by
boldly  using  two  sets  of  weights,  one  for  receiving  and
one  for  paying,  and  is  intended  to  compensate  for  the
labor  of  weighing  ingots  and  lumps  of  silver  of  no  fixed
weight,  and  for  the  risk  incurred  and  expert  knowledge
requisite  for  taking  in  silver  of  unknown  degrees  of  fineness.
The  practice  is  defended  on  the  same  ground  as  that  of  the
foreign  exchange  banks  in  quoting  different  buying  and
selling  rates  for  bills  of  exchange.
Kuping  Tael
The  Kuping  tael  is  the  currency  in  which  are  collected
all  other  dues  to  the  government  than  Customs  duties,
excepting  only  those  which  are  levied  in  kind  (such  as  the
grain  tribute)  or  in  copper  cash.  Theoretically  uniform
throughout  the  Empire,  there  are  still  differences  to  be
observed  apart  from  the  differentiated  receiving  and  paying
rates  referred  to  above!  In  one  aspect  this  tael  may  be