THE  CURRENCY  125
or  / 4 -  tael  when  first  introduced  *  (though  this  may  be  an
erroneous  assumption),  and,  as  far  as  numismatics  can  tell
us,  they  continued  to  be  of  the  same  weight  down  to  the
time  when  they  were  displaced  by  the  Tang  coins,  of  about
the  same  size,  and  of  a  statutory  weight  of  tael -  disregarding ­
  any  difference  of  tael,  this  continued  to  be  the
desideratum  of  the  mints,  the  actual  weight  of  the  issues
varying,  however,  according  to  the  laws  of  supply  and
demand,  to  the  varying  ratio  between  silver  and  copper,
and  to  the  ostensible  necessity  of  maintaining  a  bimetallic
proportion  in  the  currency,  but  seldom  falling  below  -joo
tael.  During  the  first  reign  of  the  Tsing  Dynasty  the
weight  was  yg  tael,  afterwards  raised  to  yyyõ  tael,  and  under
Kanghi,  a.d.  1684,  the  weight  was  again  reduced  to  y^  tael,
to  be  again  raised,  a.d.  1702,  to  y^y  tael,  and  again  reduced
to  yyo  tael.  This  continued  to  be  the  statutory  weight
through  the  reign  of  Yungcheng  and  into  the  beginning  of
that  of  Kienlung  (a.d.  1736),  when  it  was  again  made  yg  tael.
During  this  long  reign  of  sixty  years  degeneration  made
progress,  in  appearance  and  in  quality,  and  in  the  size
and  weight  of  the  coins  ;  the  government  was  still  vigorous,
with  no  sign  of  dry  rot,  and  we  may  assume  that  it  was  the
*  Under  the  Chow  Dynasty,  on  the  evidence  of  the  coins,  the
liang  of  24  chu  was  probably  97-5  grains,  giving  4-06  grains  as  the
weight  of  the  chu.  The  “  First  Emperor,”  Shih  Hwangti,  in  the
twenty-sixth  year  of  his  reign  as  Prince  and  the  first  year  of  his
assumption  of  the  Imperial  dignity  (b.c.  221),  issued  an  edict  increasing ­
  the  weight  and  fixing  the  standard.  On  the  authority  of
Mr.  F.  H.  Chalfant  (Journal  N.C.B.R.A.S.  1903-4)  the  standard
was  as  follows  :—
X  chu  ..  ..  ..  ..  068  gramme  =  10-5  grains
24  chu  =  i  liang  ..  ..  16-35  grammes  =  252-5  grains
This  standard  was  probably  continued  into  the  Han  Dynasty,  which
soon  (b.c.  206)  followed  the  Tsin  ;  and  the  first  ruler  of  the  Northern
Tsi  (a.d.  550)  enacted  that  a  hundred  5-chu  coins  should  actually
weigh  500  chu,  “  otherwise  1  kin  4  liang  20  chu.”  The  actual
weight  (46  to  51  grains)  of  surviving  specimens  of  5-chu  coins  corresponds ­
  closely  with  the  theoretic  weight  (52-5  grains)  of  this  standard.
When  the  standard  was  again  raised  is  not  on  record  ;  but  the  first
Tang  coins  issued  seventy  years  later  (a.d.  618)  were  presumably
one-tenth  of  the  modern  liang  of  570  to  580  grains.