114 
I^xpevimenfs  of  the  late  Mr.  Janies  Mason. 
larger  “ total  ” amount  of  the  same  constituent  remaining 
undissolved  in  the  weak  citric  acid. 
Table  I.  shows  the  results  of  one  such  series  of  analyses  ; the 
figures  give  the  percentages  of  total  nitrogen,  potash,  and 
phos{)horic  acid  present  in  the  soil  both  at  starting  and  after 
weathering,  also  the  quantity  of  the  same  constituents  which 
may  he  regarded  as  available  for  plant  food,  i.e.,  the  j)hos- 
phoric  acid  and  potash  soluble  in  a 1 per  cent,  solution  of  citric 
Table  I. — Result  of  Analysis  of  Subsoils  sent  to  Dr.  Bernard 
Dyer,  on  December  5,  1894. 
Taken  before  weathering  Taken  after  weathering 
I'hos.  acid 
Potash 
Phos.acid 
Potash 
Field 
No. 
Dissolved  by 
Dissolved  by 
i Dissolved  by 
Dissolved  by 
1 
Strong 
hydro- 
chloric 
acid 
Weak 
citric 
acid 
Strong 
hydro- 
chloric 
acid 
Weak 
citric 
acid 
lihydro- 
Ichloric 
acid 
Weak 
citric 
acid 
strong 
hydro- 
chloric- 
acid 
Tot.\i, 
Weak 
citric  i 
acid 
1 
181 
•0.37 
•0026 
•383 
•0072 
•034  i -042 
•0030 
•396 
1 
•0190  ! -036 
189 
•052 
•0019 
•637 
•0074 
•042  ' -051 
•0058 
*507 
•0172  ; -042 
197 
•035 
•0033 
•486 
•0146 
•036  035 
•0020 
•407 
•0205  036 
409 
•128 
•0015 
•275 
•0067 
•060  132 
•0015 
*267 
•0119  -065 
199 
•046 
•0019 
•244 
•0071 
•044  -044 
•0018 
•290 
•0150  -047 
226 
•028 
•0017 
•272 
•0145 
•050  ii  033 
1 
•0020 
•310 
•0219  1 -053 
Mean 
•056 
•0022 
•0096 
•044  ' -056 
•0027 
— 
•0176  1 -047 
acid.  The  results  show,  of  course,  no  change  in  the  “total” 
amount  of  any  mineral  constituent,  the  differences  being  only 
those  due  to  the  inevitable  errors  of  sampling  and  tinalysis. 
Even  the  nitrates  show  no  change,  the  trifling  amount  present 
after  weathering  being  within  the  limits  of  experimental  error. 
This  lack  of  oxidation  of  the  store  of  subsoil  nitrogen  may  he 
attributed  partly  to  the  want  of  the  appropriate  organisms,  for 
the  bacteria  converting  other  nitrogen  com[)ounds  into  nitrates 
are  only  sparingly  found  below  the  layer  of  soil  which  is 
actually  stirred  during  cultivation,  l^robably  also  the  nitrogeii 
compounds  in  an  undisturbed  subsoil  of  this  kind  are  not 
capable  of  nitrification,  having  become  so  Intumenised  as  to  be 
incapable  of  further  change,  although  originally  of  vegetable 
