144  THE  CHINESE  EMPIRE
and  fixed  ratio  of  convertibility  between  the  coppei  and
the  silver  currency  of  the  Empire  ;  and  among  the  many
facts  which  show  this,  I  need  only  refer  to  the  few  whic
have  been  mentioned  above.  The  Tang  coinage  of  t  e
seventh  century  a.d.  was  based  on  the  trimetallic  ra  i°
of  i  gold  =  io  silver  —  1,000  copper  ;  in  the  paper  money
issues  of  the  Southern  Sung  and  the  Yuan,  from  the  twe  tito ­
  the  fourteenth  centuries,  the  tiao  or  string,  or  thousan  &gt;
of  paper-money  cash  and  the  tael  of  silver  are  always
regarded  as  synonymous  terms  (c./  Marco  Polo,  ubi  supra),
notwithstanding  the  fact  that  the  paper  money  was  muc
depreciated  ;  and  the  first  Manchu  Emperor  (a.d.  1644h
in  his  desire  to  conform  in  every  way  to  Chinese  theory
and  practice,  inscribed  on  his  coins  their  theoretic  silver
value,  Y\hòõ  of  a  tael.
Silver  Coins
Five  centuries  after  the  Tang  rulers  had  either  fixed  the
bimetallic  ratio  or  had  adopted  that  which  they  found  in
existence,  silver  had  appreciated  to  double  its  value  in  its
relation  to  copper  cash,  one  shoe  of  50  taels  of  silver  exchanging ­
  for  100,000  cash  ;  and  about  a.d.  1183,  during
the  reign  of  Hiaotsung,  the  second  Emperor  of  the  Southern
Sung,  China  for  the  first,  and  (until  a  few  years  ago)  las
and  only  time,  minted  silver  coins.  There  were  five  kinds,
weighing  1,  2,  3,  5,  and  10  taels  respectively,  each  tael
passing  for  2,000  cash.  They  could  be  used  as  official
and  commercial  currency,  and  served  equally  as  metallic
reserve  for  the  paper  notes.  This  silver  coinage  only  lasted
three  years.
I  am  uncertain  whether  we  should  regard  this  as  a  true
silver  coinage  of  which  the  face  and  intrinsic  values  should
correspond,  or  whether  it  was  not  an  issue  of  depreciated
silver  token  currency  intended  to  serve  mainly  as  metallic
reserve  to  support  the  still  further  depreciated  paper  currency ­
  ,  the  issues  of  which  under  the  same  dynasty  had  begun
fifty  years  before  ;  a  fair  parallel,  were  it  not  for  the  relative
credit  of  the  two  governments,  might  be  found  in  the  silver