148  DISINFECTION  OF  NITROGENOUS  MANURE. 
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formula :  (N  C2  H,  02)  NH3;  it  is  therefore  urenoxyd-am- 
monia.  Now,  this  urea  is  rapidly  decomposed  even  at  ordinary 
temperatures,  and  its  elements,  with  two  atoms  of  water,  form  two 
atoms  of  ammonia  and  two  of  carbonic  acid,  (N  C2  H,  02)^N 
H3  -f  2  H  0—2  1ST  H3  +  2  C  02.  Both  of  these  products  are 
volatile,  and  therefore,  if  urine  be  allowed  to  decompose,  the 
most  valuable  constituents  for  manure  are  lost  in  the  atmosphere. 
In  estimating  guano  the  nitrogen  is  the  true  standard  of  value. 
Estimating  night-soil  in  the  same  manner,  and  assuming  that  we 
preserve  all  the  nitrogen,  the  city  of  New  York  and  environs 
would  afford  manure  equal  in  value  to  51,000  tons  of  best  Peru- 
vian guano,  or  $2,550,000  per  annum.    During  the  last  seven 
years,  according  to  the  Report  of  the  Patent  Office  for  1854, 
the  United  States  has  imported  on  an  average  45,869  tons  of 
guano  annually.,    Much  of  this  guano  is  worthless,  being  so  when 
first  obtained,  or  having  been  washed  in  order  to  manufacture 
ammoniacal  salts  for  sale.    The  practice  of  washing  guano  is  a 
common  trick  of  trade,  and  usually  a  safe  one,  since  farmers 
never  employ  a  chemist,  and  washed  guano  can  be  bought  at  a 
comparatively  low  price.    But  even  estimating  all  the  imported 
guano  as  equal  to  the  best  Peruvian,  worth  $50  per  ton,  it  would 
amount  to  but  $2,293,450,  which  is  less  by  $256,550  than  the 
value  of  the  night-soil  of  the  city  of  New  York,  as  above  esti- 
mated.   Great  Britain  has  imported  on  an  average  during  the 
last  seven  years,  138,496  tons  of  guano  per  annum,  which,  at 
$50  per  ton,  amounts  to  $6,924,800.    The  night-soil  of  London 
and  environs  would  yield  annually  nitrogen  corresponding  to 
120,000  tons  of  best  Peruvian  guano,  and  would  doubtless  ex- 
ceed the  amount  of  nitrogen  imported.    As  long  ago  as  1834,  it 
was  estimated  that  London  wasted  manure  (principally  night-soil 
in  the  Thames)  to  the  amount  of  $2,000,000  per  annum.  How 
much  London  or  New  York  now  wastes  I  am  not  informed ;  but 
all  will  agree  that  public  health  and  the  interests  of  agriculture 
most  earnestly  demand  a  thorough  sanitary  reform  of  all  our 
cities  and   towns  National  Intelligencer,  Washington.  Dec. 
12,  1855. 
