392 
Meteorology . 
The  mineral  theory  hastily  adopted  by  Liebig  has  broken 
down  ; no  other  has  taken  its  place.  Our  best  authority,  Mr. 
Lawes,  has  established  certainly  so  much,  that  of  the  two  active 
principl  es  in  manure,  ammonia  is  specially  suited  to  corn,  phosphorus 
to  turnips,  and  that  turnips  are  probably  benefited  by  the  woody 
matter  of  straw.  But  vegetable  chemistry,  having  no  fixed  truths  of 
lier  own  as  to  the  sources  from  which  plants  derive  their  food  or 
the  mode  in  which  they  appropriate  it,  is  not  advanced  enough  to 
lay  down  laws  for  farming,  or  sit  in  judgment  on  its  established 
practices.  Except  Liebig’s  suggestion  for  dissolving  bones  with 
acid,  and  Sir  Robert  Kane's  for  using  flax-water  as  manure,  I 
know  no  agricultural  process  arising  out  of  chemical  discovery. 
The  more  >ve  value  the  labours  of  agricultural  chemists,  the  more 
warmly  we  look  forward,  as  I do,  to  their  future  progress  through 
the  patient  examination  of  existing  practice,  which  is  itself  the 
accumulated  and  varied  science  of  ages,  the  more  we  should  dis- 
courage undue  expectations  of  immediate  advantage.  It  is  a great 
mistake  to  suppose  that  men  can  be  made  farmers  by  teaching 
them  doubtful  chemistry.  But  are  we,  therefore,  to  abandon 
agricultural  chemistry  because  it  is  yet  doubtful,  and  has  not  yet 
brought  forth  more  fruit?  Rather  let  those  who  are  able  cultivate 
it  the  more  diligently  by  careful  experiments,  that  step  by  step 
we  may  reach  more  certain  knowledge  hereafter.  No  one,  mean- 
while, can  doubt  the  high  value  of  Mr.  Lawes’s  experiments  in 
the  field,  or  Mr.  Wav’s*  researches  in  the  laboratory.  I should 
not  have  said  so  much,  but  that  the  public  are  sometimes  led  by 
a false  estimate  of  chemistry  to  undervalue  our  real  progress  in 
other  sciences,  as  in  mechanics,  and  to  overlook  the  true  know- 
ledge of  our  practical  farmers.  Before  we  pass  to  these,  how- 
ever, I must  endeavour  to  do  justice  to  our  advance  in  what 
seems  the  most  uncertain  of  all  sciences — 
Meteorology. 
Much  light  has  lately  been  thrown  on  climate ; and  our  own, 
which  was  once  so  much  complained  of,  is  found  to  be  the  best  in 
the  world  for  healthful  exercise,  and,  as  I believe,  for  farming 
also  : because  it  enjoys  the  most  temperate  summer,  combined 
with  the  mildest  winter,  and,  on  the  whole,  a steady  down-fall  of 
rain.  No  one  can  have  returned  from  Calais  to  Dover  without 
admiring  the  refreshing  verdure  of  the  English  downs.  This  we 
owe  to  our  frequent  showers,  to  our  clouded  sky,  shielding  off  the 
scorching  sunshine,  and  to  invisible  vapour  diffused  in  our  air. 
The  excess  of  vapour  is  shown  by  the  difficulty  of  growing  in 
French  greenhouses  the  heath,  a plant  requiring  moist  air,  and  the 
difficulty  of  working  the  English  electric  telegraph.  This  moisture 
* See  Mr.  Way  s excellent  paper  on  Guano.  Journal,  vol.  x.,  p.  196. 
