418 
Management  of  Manure. 
made  dung  more  or  less  of  this  volatile  ammonia  is,  in  some 
unknown  way,  brought  again  into  a fixed  state.  Sprengel  thinks 
this  is  brought  about  by  humic  acid,  arising  from  the  decom- 
position of  straw.  Liebig  denies  the  existence  of  such  an  acid, 
but  says  that  decayed  woody  fibre  has  the  power  of  absorbing 
ammonia  to  seven  hundred  times  its  own  bulk. 
Much  ammonia,  it  seems  likely,  must  be  fixed  in  some  way, 
because  in  dunghills  which  are  ripe,  and  yet  not  decayed,  one 
perceives  little  or  no  pungency  of  scent,  while  practice  shows  that 
such  dung  has  not  lost  its  vigour.  There  is  danger  then,  that  after 
all  in  applying  the  liquid  portion  apart,  we  may  dissipate  the 
very  essence  we  are  seeking  to  save,  which  would  otherwise 
have  been  fixed  by  a natural  process.  Supposing,  however,  that 
we  adhere  to  the  old  practice  of  making  dung  in  farm-yards 
with  the  help  of  the  rain  from  heaven,  there  remains  the  objec- 
tion that  the  supply  is  sometimes  in  excess,  and  that  a black 
stream  runs  away  into  some  neighbouring  ditch.  This  picture, 
a very  common  one,  is,  I think,  somewhat  overdrawn ; or  rather, 
is  sketched  from  dairy  farms,  where  litter  is  scarce.  On  arable 
farms  1 doubt  if  the  waste  be  very  great.  Much  will  depend, 
of  course,  on  the  average  amount  of  rain,  which  varies,  as  we 
have  seen,  in  different  counties.  I have  no  experience  on  the 
matter,  because  my  own  yards  have  their  vent  upon  catch- 
meadows,  over  which  the  waste  fluid  is  dispersed  by  the  stream 
that  runs  through  each  yard  ; but  Mr.  Thompson’s  plan  of  a tank, 
as  improved  by  Mr.  Hannam,*  seems  perfect.  The  farm-yard 
should  be  hollow  in  one  part,  and  drains  from  the  stables  may 
empty  into  this  part.  Here  straw  may  accumulate,  and  be  steeped 
in  the  muckwater.  To  prevent  its  overflow,  a drain  should  be 
led  from  the  upper  level  of  this  hollow  to  a tank  out  of  the  yard, 
and  by  the  side  or  in  the  centre  of  a paved  hollow  like  a shallow 
gravel  pit.  When  the  yard  is  cleared  .the  dung  can  be  deposited 
in  this  pit,  and  the  liquid  from  the  tank  be  pumped  over  it  as 
occasion  requires.  I should  add  a well  in  case  of  dry  weather, 
when  the  liquid  in  the  tank  might  not  suffice  to  keep  the  heat 
moist  without  the  use  of  plain  water.  “Plain  water,”  says  Mr. 
Thompson,  “ has  been  found  to  answer  exceedingly  well.” 
When  the  manure  is  to  remain  long  in  the  pit,  it  is  covered  with 
soil,  and  both  moisture  and  gas  are  so  completely  retained,  that 
nine  people  in  ten  might  walk  unconsciously  over  it. 
A still  simpler  plan,  I think,  would  be  the  following.  Let 
the  straw-yard  be  shaped  hollow  to  the  centre,  like  a shallow 
dish.  In  the  centre  might  be  the  tank,  surrounded  by  a low  wall, 
and  from  thence,  with  a pump  and  hose,  you  might  easily  return 
* See  Mr.  Hannam ’s  account,  reprinted  at  the  end  of  this  paper,  from  the  Journal 
of  V orkshire  Agricultural  Society,  1843. 
