On  the  Power  of  Soils  to  absorb  Manure ; 319‘ 
analysed ; by  his  permission  the  result  of  the  analysis  is  now 
given : — - 
Analysis  of  Mr.  Pusey’s  Soil. 
When  dried  in  the  air,  100  parts  contain — - 
Water  
. 20-56 
Vegetable- matter 
. 617 
Sand  and  clay  (insoluble  in  acids)  . 
. 59  00 
Phosphoric  acid  . ' 
Carbonate  of  lime 
Magnesia-  . 
Oxide  of  iron  and  alumina  . 
. 7-90 
Soda*'1  | dissolved  out  by  acids  j 
. 0-31 
. 0-12 
. . . . . , 
100-00 
Mr.  Huxtable’s  soil  was  not  analysed,  but  the  pottery  clay,  to 
which  it  will  be  frequently  necessary  to  allude,  was  carefully  ex- 
amined. The  clay  in  question  is  a white  bed  of  the  “ plastic  clay  ” 
formation,  which  is  worked  for  the  purposes  of  pottery  in  the. 
neighbourhood  of  Farnham.  It  was  obligingly  furnished  to  me 
by  Mr.  Paine  ; the  masses  sent  up  were  taken  from  a depth  of 
nearly  20  feet  from  the  surface  ; and  it  is  remarkable,  as  an  instance 
of  the  tendency  of  clay  to  unite  with  ammonia,  that  a small  portion 
taken  from  the  centre  of  the  mass  (and  which  had  consequently 
no  opportunity  of  absorbing  any  gaseous  substance  from  the  air) 
was  found  to  give  off  abundance  of  ammonia  when  heated  in  a 
tube. 
There  are  two  possible  ways  in  which  the  clay  might  have  ac- 
quired this  ammonia — either  in  the  course  of  ages  water,  pene- 
trating to  the  depth  of  20  feet  through  a most  impervious  stratum 
of  clay,  may  have  carried  with  it  some  portion  of  ammonia  ; or  the 
clay  must  have  absorbed  ammonia  from  the  water  in  which  at  a 
remote  geological  period  it  was  suspended  before  deposition  in  its 
present  place. 
The  first  of  these  suppositions  is  improbable  on  account  of  the 
almost  physical  impossibility  of  water  percolating  the  mass,  and 
because,  as  the  clay  is  not  nearly  saturated  with  ammonia,  it 
would  not  have  been  likely  to  have  reached  these  inferior  layers 
at  all. 
There  is  little  doubt,  therefore,  that  the  ammonia  found  in  the 
clay  was  derived  from  organic  bodies  decaying  in  the  very  water 
from  which  the  clay  was  deposited.  We  could  hardly  have  a more 
striking  instance  of  its  power  of  absorption  and  retention  of 
ammonia  in  despite  of  water,  to  the  action  of  which  it  must  have 
been  at  that  time  exposed  for  a very  lengthened  period. 
