Oct.  1899. 
Annual  Report  of  the  Director. 
367 
age  section  and  a  larger  and  more  complete  work-room,  to  which 
three  tables  have  been  added  for  the  accommodation  of  specialists 
and  monographists  who  desire  to  use  the  collections  for  research. 
The  growth  of  the  collections  has  been  so  large  and  the  charac- 
ter so  excellent  that  this  section  of  the  department  now  takes 
high  rank  as  the  largest  herbarium  in  the  Central  United  States, 
while  the  methods  of  installation  and  recording  of  specimens 
establishes  its  usefulness.  The  labor  of  arranging  the  large  amount 
of  departmental  material  for  exchange  has  progressed  favora- 
bly. Over  5,000  plants  have  been  mounted,  poisoned,  and  installed 
in  the  cases,  and  over  2,000  identified,  classified,  and  prepared  for 
publication.  Hall  70,  devoted  to  coals  and  hydrocarbons,  has  been 
entirely  rearranged  and  the  collections  newly  installed.  Many  of 
the  specimens,  especially  the  larger  ones,  had  not  before  been  cased 
and  were  suffering  from  dust  and  disintegration.  Wall  cases,  8 
feet  high  and  from  17  to  29  inches  deep,  have  accordingly  been  pro- 
vided, and.  these,  with  four  floor  cases,  furnish  casing  for  all  the 
specimens.  In  order  to  guard  against  danger  from  spontaneous 
combustion,  the  case  containing  the  larger  specimens  has  been 
lined  at  the  base  with  asbestos  millboard  ^-inch  thick,  and  the 
adjoining  walls  have  been  covered  with  two  thicknesses  of  asbestos 
paper.  The  interiors  of  all  the  cases  have  also  been  painted  with 
asbestos  paint.  Many  of  the  specimens  in  the  form  of  blocks,  6x6x10 
inches  in  size,  have  been  treated  by  soaking  twenty-four  hours  in  thin 
shellac  in  order  to  prevent  disintegration.  For  exhibiting  lump  coal 
or  coal  in  broken  fragments,  a  form  of  metallic  tray  was  devised  which 
serves  admirably  for  purposes  of  exhibition.  The  form  (illustrated 
elsewhere)  is  that  of  a  deep  tray  with  two  sides  divergent,  cut  down  in 
front  to  a  narrow  strip  the  contents  giving  support  to  the  label. 
The  tray  is  made  of  tinned  iron,  bound  at  the  edges  with  wire 
and  enameled  a  drab  color  outside  and  white  inside.  It  is  be- 
lieved it  will  be  found  admirably  adapted  for  exhibiting  other  loose 
substances,  such  as  clays  and  earthy  minerals,  in  upright  cases.  To 
the  specimens  formerly  exhibited  in  the  hall  have  been  added  a 
number  of  new  series  recently  received  by  gift  or  collection  or 
brought  from  storage,  so  that  the  collections  now  fully  illustrate 
the  varieties,  origin  and  uses  of  coals  and  mineral  hydrocarbons. 
The  collections  in  Hall  78,  devoted  to  non-metallic  minerals  of 
use  in  the  arts,  have  been  entirely  rearranged  in  order  to  make  room 
for  new  material  and  rectify  the  classification.  Four  new  cases 
have  been  added,  and  the  interiors  of  all  the  cases  have  been 
painted  black.     Among  the  new  material  added  are  two  collections 
