THE  PROVINCES  AND  THE  TREATY  PORTS  223
treaty  ports.  It  lies  between  Szechwan  to  the  north,
Yunnan  to  the  west,  Kwangsi  to  the  south,  and  Hunan  to
the  east,  and  has  an  area  estimated  at  67,000  square  miles,
and  population  at  7,500,000.  It  is  rich  in  minerals,  especially ­
  of  the  less  common  kinds,  and  its  products,  of  which
opium  is  the  most  important,  find  their  outlet  through
Hunan  and  Kwangsi.

Szechwan
Szechwan,  the  “  Four  Streams,”  has  an  area  calculated
to  be  218,500  square  miles.  Nothing  better  illustrates
the  uncertainty  impending  over  everything  statistical  in
China  than  the  variability  of  the  estimates  of  its  population. ­
  The  estimates  made  within  the  last  twenty  years
have  ranged  from  35,000,000  (Hobson,  1892)  to  79,500,000
(Popoff,  1894)  ;  but  the  general  tendency  of  investigators
has  been  to  put  it  between  50,000,000  and  65,000,000;  Parker
(1903)  is  inclined,  however,  to  doubt  all  the  high  estimates  ;
and  Hosie  (1904),  than  whom  few  have  studied  the  province
more  carefully,  puts  it  at  45,000,000.  The  surface  of  the
province  is  made  up  of  masses  of  mountains,  through
which  the  Yangtze  has  cut  its  deep  and  narrow  channel,
and  which  is  everywhere  cut  up  by  steep-sided  valleys  and
ravines.  In  the  whole  province  there  is  but  one  extensive
plain,  that  of  Chengtu,  the  capital,  on  which  the  irrigation
system  is  among  the  wonders  of  the  world.  Among  the
minerals  found  are  gold,  silver,  cinnabar,  copper,  iron,
coal,  and  petroleum,  and  among  its  natural  products  the
chief  are  opium,  hemp,  white  wax,  yellow  silk,  and  some
hundreds  of  products  of  its  hills  and  valleys  included  in
the  Chinese  pharmacopoeia.  Chief  among  the  products  of
this  rich  province  is  salt,  obtained  from  artesian  borings,
some  of  which  extend  2,500  feet  below  the  surface,  and  from
which  for  centuries  the  brine  has  been  laboriously  raised
by  windlass  and  water  buffalo  power.  The  one  outlet  for
Szechwan,  except  at  the  cost  of  toilsome  mountain  journeys,
is  by  The  Great  River  (Kiang)  or  The  Long  River—
the  river  otherwise  without  a  name,  the  spinal  cord  of  China,