and  Subsoils  of  some  of  the  Fields  at  Rothamsted.  357 
of  October.  Towards  the  end  of  February  1882  the  land 
was  harrowed  and  rolled.  The  samples  of  soil  were  taken 
between  February  24  and  March  7.  The  quantity  of  nitrogen 
as  nitric  acid  found  in  the  soils  and  subsoils  of  the  various 
plots  will  be  found  in  Table  VIII. 
Table  VIII. — Nitrogen  as  Nitrates  in  the  Soil  and  Subsoil  of 
various  Plots  in  Hoos  Barley  Field,  March  1882.* 
Nitrogen  as  Nitrates  in  lbs.  per  acre. 
Plot. 
Maxciuxg. 
First 
Second 
Third 
Total 
Nine 
Nine 
Nine 
Twenty- 
Inches. 
Inches. 
Inches. 
Inches. 
lbs. 
lbs. 
lbs. 
lbs. 
lo. 
Unmanured 
5-9 
4-7 
. 5-1 
15-7 
2o. 
Superphosphate 
6-4 
5-7 
6-3 
18-4 
3o. 
Sulphates  of  Alkalies 
6-1 
5-7 
6-5 
18-3 
4o. 
Mixed  Mineral  Manure 
7-5 
9-7 
[6-3] 
23-5 
Mean  of  Series  . . 
6-5 
6-5 
6-1 
19-0 
1 A. 
200  lbs.  Ammonium-salts  .. 
6-1 
8-3 
7-0 
21-4 
2 A. 
Ditto,  with  Superphosphato 
7-4 
11-5 
8-2 
27-1 
3 A. 
Ditto,  with  Sulphates  of  Alkalies 
7-5 
6-2 
5-6 
19-3 
4 a. 
Ditto,  with  mixed  Min.  Manure 
8-1 
5-8 
8-9 
22-8 
Mean  of  Series  .. 
7-3 
8-0 
7-4 
22-7 
1 aa. 
275  lbs.  Nitrate  of  Sodium . . 
9-7 
6-8 
9-0 
25-5 
2 aa. 
Ditto,  with  Superphosphate 
7-8 
10-4 
8-3 
26-5 
3 AA. 
Ditto,  with  Sulphates  of  Alkalies 
7-8 
6-2 
8-1 
22-1 
4 AA. 
Ditto,  with  mixed  Min.  Manure 
9-4 
5-7 
6-2 
21-3 
Mean  of  Series  . . 
8-7 
7-3 
7-9 
23-9 
1 c. 
1000  lbs.  Rape  Cake 
10-6 
13-7 
7-9 
32-2 
2 c. 
Ditto,  with  Superphosphate 
7-5 
13-1 
7 8 
28-4 
3 c. 
Ditto,  with  Sulphates  of  Alkalies 
10-6 
11-2 
9-5 
31-3 
4 c. 
Ditto,  with  mixed  Min.  Manure 
8-2 
11-5 
8-7 
28-4 
Mean  of  Series  . . 
9-2 
12-4 
8-5 
30-1 
71  { 
Unmanured,  1872-81  (Farmyard-1 
manure,  1852-71) J 
14-8 
11-8 
10-9 
37-5 
72 
14  tons  Farmyard-manure 
18-6 
14-6 
10-9 
44-1 
The  experimental  difficulties  referred  to  in  the  case  of  Broad- 
balk  Field  have  proved  equally  great  in  the  investigation  now 
before  us  ; we  must  be  content,  therefore,  to  seize  the  general 
features  of  the  results,  without  expecting  perfect  accuracy  in 
