Although  certain  research  had  been  made  upon  this  subject,  they  needed  confirma-
tion by  new  examination,  for  which  reason  the  commission  chai'ged  with  the  direction
of  certain  German  forestal  experiments,  decided  to  undertake  more  extended  observa-
tions concerning  bark  suitable  for  tanning.  To  obtain  a  more  speedy  conclusion,  these
experiments  were  in  Prussia,  made  upon  oJd,'^  and  in  Baden  and  Wiirtemburg  upon
yoiuig  trees.
In  Wiirtemberg,  oak-bark  is  divided  for  market  into  the  three  following  sorts:

1.  Glossy  or  shiniug  hark,  obtained  from  all  trees  less  than  12  centimeters  (4^  inches)
in  diameter,  including  the  bark,  whether  creviced  or  not.
2.  Average  bark,  i.  e.,  bark  both  of  stem  and  branches,  from  trees  and  shoots  cut  la
the  working  of /itfaie,^  and  from  12  to  24  centimeters  (4^  to  9  inches)  iu  thickness.
3.  Coarse  bark,  including  the  bark  of  trunk  and  of  all  branches  of  trees  over  24
centimeters  iu  diameter.
The  price  of  the  second  is  generally  seven-tenths  as  much  as  the  first,  and  the  third
is  sold  separately,  the  unit  in  all  cases  being  the  quintal.
Glossy  bark  is" found  chitfly  in  copi>ices  managed  specially  for  the  production  of  bark,
with  a  revolution  of  fifteen  to  thirty  years,  or  in  the  underwood  of  coppice  mingled
with  large  timber;  or,  less  frequently,  in  the  trees  cut  iu  the  lirst  thinning  of  futaie
Average  bark  comes  chiefly  from  the  younger  reserves  of  coppice,  mingled  with  large
timber,  and  thinning  of  trees  fifty  to  eighty  years  old.  Coarse  bark  comes  from  old
oaks,  of  all  descriptions,  wherever  it  appears  worth  saving,  The  experiments  reported
related  chiefly  to  the  first  and  second  of  these  classes.
