FOREIGN  TRADE  295
silk  came  chiefly  from  Manchuria,  with  secondary  sources
of  supply  in  Szechwan  and  Kwangtung  ;  waste  silk  came
from  many  quarters  ;  and  woven  silks  were  produced
chiefly  in  the  vicinity  of  Nanking,  Soochow,  Hangchow,
Shanghai,  and  Canton,  and,  in  the  shape  of  pongees  woven
from  wild  silk,  at  Chef00.  Of  all  these  products  raw  white
silk  is  the  most  important,  and  this  is  mainly  produced
within  a  radius  of  150  miles  around  Shanghai,  and  in  a
smaller  district  around  Canton  :  of  the  two  the  Shanghai
silk  is  of  the  finer  quality.  In  this  district  the  silkworm
is  by  nature  the  best  in  the  world,  producing  naturally  from
the  best  mulberry  the  largest  quantity  of  the  finest  silk  ;
and  formerly,  in  silk  as  in  tea,  China  set  the  standard  for
the  world.  In  the  course  of  years  the  silkworm  all  over
the  world  was  attacked  by  disease.  In  Europe,  and  later
in  Japan,  scientific  remedial  measures  were  evolved  by
patient  study,  with  the  result  that  the  disease  can  make
no  headway  there,  and  with  the  further  result  that  their
silk  is  much  improved  in  quality.  China  had  for  centuries
adopted  a  method  of  eliminating  the  weaklings  from  the
eggs  by  exposure  to  frost  and  snow,  a  method  more  effective
than  any  adopted  in  Europe,  and  fully  effective  so  long
as  no  disease  attacked  the  eggs  or  the  worms  ;  but  her
failure  to  adopt  the  scientific  remedy  of  microscopic  examination ­
  is  by  degrees  putting  her  behind  in  the  race.  Of
1,000  eggs  passed  as  healthy  by  this  test  it  may  be  said
that  700  will  survive  through  all  the  stages  of  moulting
and  development,  and  will  spin  strong  full-sized  cocoons,
of  which  it  will  take  3  to  4  lbs.  to  reel  1  lb.  of  silk  ;  of  1,000
eggs  passed  by  the  test  of  frost  alone,  700  may  hatch  out,
and  of  these  700,  fully  400  will  die  during  the  successive
moults,  having  meantime  eaten  leaf  to  waste,  and  the
surviving  300  will  spin  weak  under-sized  cocoons,  of  which
it  will  take  6  to  7  lbs.  to  reel  1  lb.  of  silk.  The  proportion
between  the  producing  capacity  of  the  Italian  and  the
Chinese  silkworm  may  be  put  at  100  to  25,  apart  from  the
waste  of  leaf.  Once  upon  a  time  China  was  the  sole  source
of  supply  of  silk  for  the  West,  and  within  a  half-century  she