236         BOTANY  IN  ITS  BEARINGS  ON  PHARMACY,  ETC. 
Besides  these,  there  are  special  houses  for  the  ferns,  the  begonias 
cacti,  and  the  orchideous  plants  and  tropical  tree-ferns.  There  is  also  a 
tropical  aquarium  for  water  plants,  36  feet  in  diameter,  which  has  fine 
specimens  of  the  Yictoria  regia,  nymphaeas,  etc. 
An  exceedingly  interesting  part  of  the  grounds  is  that  laid  out  in 
beds,  and  devoted  to  annuals  and  herbaceous  perennials,  and  especially 
those  used  in  medicine  ;  yet  they  bear  a  very  small  relation  in  extent  to 
the  other  portions  of  the  garden.  Nowhere  else  did  we  see  such  ample, 
unlimited  room  for  all  purposes,  whether  the  subject  was  a  gigantic  cedar 
or  a  tiny  rhodendron,  or  a  bed  of  annuals  ;  there  is  no  cramping,  as  in 
most  of  the  botanical  gardens  of  the  continent,  hedged  in  by  the  houses 
and  streets.  And  then  the  arboretum  !  Think  of  270  acres  laid  out  in 
walks  and  avenues,  with  noble  trees  drawn  from  all  countries  which  can 
be  acclimated,  planted  in  generic  groups,  so  that  one  may  see  the  ma- 
ples of  California  and  Oregon  side  by  side  with  those  of  the  Atlantic 
States  and  Europe.  Very  fine  oaks,  elms,  beeches,  birches,  hickories, 
and  cedars,  and  a  pinetum,  with  representatives  from  almost  all 
temperate  countries,  southern  and  northern.  Besides  these  living  speci- 
mens, Kew  contains  an  extensive  herbarium,  which  has  grown  rapidly  of 
late  years.  Dr.  Hooker,  in  his  report  for  1865,  speaks  of  eighty  donations, 
representing  in  all  nearly  100,000  plants  from  all  parts  of  the  world,  and 
especially  Brazil  and  Africa,  as  having  been  received.  In  fact,  the  herba- 
rium is  the  largest  in  existence,  and  constantly  increasing,  and,  together 
with  the  library,  forms  a  great  centre  of  botanical  research,  where  a 
corps  of  botanists,  to  the  number  of  fifty,  are  permitted  to  make  their 
investigations. 
Another  feature  due  to  the  late  Sir  William  J.  Hooker,  are  the  muse- 
ums of  ecouomic  botany,  commenced  in  1847,  the  first  of  their  kind 
established,  and  by  far  the  most  extensive  in  the  world.  The  universal 
exhibitions,  1851  and  1862  at  London,  and  1855  at  Paris,  gave  large  ac- 
cessions to  the  collection,  and  we  have  no  doubt  it  will  be  increased 
largely  from  the  vast  collections  of  natural  vegetable  products  in  the 
Paris  Exhibition,  1867.  "The  object  of  the  museums  is  to  show  the 
practical  application  of  botanical  science."  We  can  there  learn  the  re- 
lations of  the  vegetable  world  to  man,  what  our  food,  timber,  and  medi- 
cines come  from,  and  how  much  besides  a  knowledge  of  flowers  and  leaves 
may  be  derived  from  a  study  of  botany.  There  are  three  museums.  In 
the  first  and  second  the  products  are  arranged  according  to  the  botanical 
natural  orders,  and  the  first  museum  includes  the  products  from  dicoty- 
ledonous plants,  the  second  those  from  monocotyledons  and  acotyledons, 
whilst  the  third  museum  is  devoted  to  the  specimens  of  timber  and  bulky 
articles,  and  is  largely  made  up  of  the  products  of  the  British  colonies. 
The  concentration  of  so  much  that  is  beautiful  and  interesting  in  na- 
ture, arranged  with  special  reference  at  once  to  the  gratification  of  the 
public  and  the  advancement  of  science,  renders  Kew  Gardens  one  of  the 
