Management  of  Manure. 
417 
simply  to  the  use  of  the  liquid.  The  mere  mowing  would 
give  more  grass,  because  the  feet  of  animals  trampling  at 
liberty  while  they  feed  at  will,  checks  the  growth  of  the  young 
grass,  and  this  I believe  to  be  the  principal  reason  why  folding 
of  sheep,  as  already  mentioned,  should  afford  so  much  more 
keep  than  allowing  them  to  range  at  large.  The  system  seems 
specially  suited  for  cows  kept  to  supply  large  towns  with  milk, 
but  even  if  the  use  of  liquid  manure  were  desirable  as  a general 
practice,  it  seems  scarcely  suited  to  the  health  of  young  animals. 
Foreign  writers  always  ascribe  its  adoption  to  scarcity  of  litter. 
In  Switzerland,  where  it  has  been  longest  in  use,  the  straw  litter 
of  the  oattle  is  twice  a-week  withdrawn  from  their  beds,  washed, 
and  replaced  ; but  such  a scarcity  of  straw  is  certainly  not  the 
grievance  under  which  our  arable  farmers  labour. 
It  has  also  been  proposed  as  a remedy  against  the  escape  of 
liquor  to  roof  over  the  farmyard.  But  the  straw  lying  loose 
would  be  apt,  I think,  to  get  fire-fanged,  as  is  now  the  case 
with  horse  litter  thrown  too  thickly  into  the  yard  during  dry  wea- 
ther. In  this  part  of  England  the  dung  does  not  get  made  even 
in  the  open  yard  when  our  usual  scanty  allowance  of  rain  at  all 
fails.  A roof  for  the  dung-heap  has  been  further  also  suggested. 
This  may  perhaps  be  required  in  Lancashire,  but  I would  not 
venture  it  here. 
Seeing,  then,  the  lack  of  a remedy,  it  may  be  worth  while  to 
inquire  into  the  extent  of  the  disorder  j and,  first,  as  to  the 
escape  of  ammonia.  The  two  remedies  which  Boussingault,  as  a 
chemist , proposes,  are  the  exclusion  of  air  and  moisture.  “ The 
daily  addition  of  fresh  litter  from  the  stables,”  he  says,  speaking, 
indeed,  of  the  dunghill,  but  the  principle  applies  equally  to  the 
yard,  “ powerfully  impedes  the  escape  of  the  volatile  elements,  pro- 
tecting the  inferior  layers  from  the  direct  contact  of  air.”  The 
German  Thaer,  indeed,  examined  chemically  the  air  collected 
from  the  surface  of  dung-heaps,  and  found  little  or  no  escape 
either  of  carbon  or  of  ammonia.  Pressure  our  farmers  provide 
by  the  trampling  of  beasts  in  the  yard,  and  by  driving  their  carts 
over  the  dunghills.  With  plenty  of  litter  there  need  be  no 
smell,  even  in  a yard  where  eighty  hogs  are  being  fatted  at  once, 
as  I have  often  experienced,  but  the  pleasant  scent  of  fresh  wheat- 
straw.  Dry  hot  weather  is  the  time  when  most  waste  occurs  ; 
and  then  it  would  be  well,  certainly,  to  screw  a hose  on  the  pump, 
and  distribute  water  over  the  yard : for  though  chemists  differ  as 
to  the  changes  which  farmyard  dung  undergoes,  all  agree  as  to 
the  utility  of  water  in  diminishing  the  volatility  of  the  ammonia. 
They  agree  that  the  urea,  in  the  first  place,  is  a fixed  salt,  and 
that  it  becomes  volatile  as  ammonia,  but  in  what  mode  they  do 
not  agree.  They  also  agree,  which  is  important,  that  in  well- 
