On the Rain and Drainage - Waters at Rotliamsted. 
59 
Each of the otiier plots had, respectively, received the same 
description, and with immaterial exceptions the same amount, 
of manure for the last 14 years of the 22, but had been somewhat 
differently manured during the first 8 years. 
Confining attention for the present to the several artificially- 
manured plots, it is seen at a glance that, with the exception of 
Plot 10, with the ammonium-salts alone, all the plots receiving 
annually 400 lbs. of ammonium-salts show a higher per- 
centage and actual amount of nitrogen in the surface-soil than 
Plot 5 with the mineral manure without ammonium-salts ; and 
Plot 16, which, during the first 13 of the 14 years had received 
annually 800 lbs. of ammonium-salts, or twice as much as any 
of the others (but had since grown one crop without any 
ammonia) shows a higher amount still. Without claiming 
absolute accuracy for the figures, it cannot fail to be observed 
that the excess on the different plots over Plot 5, as given in 
the last column of the Table, is very closely in the order of 
the amounts of nitrogen in the crops, and almost the converse 
of the order of the amounts in the drainage, as shown in 
Table LIII. Thus, there are the highest amounts in the crop, 
and the highest amounts in the surface-soil, on Plots 7a and 9a, 
with the most complete mineral manure ; and the estimated 
loss by drainage from those plots is the lowest. There are less 
amounts of nitrogen in the crops, less in the soil, and there is 
more estimated loss by drainage, on Plots 12, 13, and 14, with 
superphosphate, and either soda, potash, or magnesia. There 
is less still in the crop, less still in the soil, and more loss in 
the drainage, on Plot 11, with only superphosphate as mineral 
manure. Finally, there is the least in the crop, no excess in 
the soil, and the most in the drainage, of Plot 10, with the 
ammonium-salts alone. 
The second and third 9 inches of soil also show in most 
cases some, but a variable amount of excess of nitrogen in the 
case of plots receiving nitrogenous manure ; but it would lead 
to too long a discussion to consider the results in any detail. 
This must be reserved for a special Report on our very numerous 
determinations of nitrogen in soils. 
It may be stated, however, that in the autumn of last year 
(1881) samples were again taken, to three depths of 9 inches 
each, or to a total depth of 27 inches, from 20 plots in the Experi- 
mental Wheat-field, and the determination of nitrogen in them 
is now in progress. With regard to the results, we can only now 
state the significant fact that, so far as the amount of nitrogen 
in the surface-soil is concerned, the relation of plot to plot is 
essentially accordant at the two periods. Thus, the determina- 
tions in 1865 were made after 14 vears, and those of 1881 after 
