204 
Ouj' Climate and our Wheat-Crops. 
after the application of the nitrate so high as might be expected ; 
though the amount has been found to be very high in individual 
cases of drainage collected soon after the spring dressing. 
Lastly, to facilitate the appreciation of the significance of the 
results given in the Table, it may be observed that, for every inch 
of rain passing beyond the reach of the roots, and containing 
one part of nitrogen as nitrates per 100,000 parts of water, there 
will be a loss of rather more than 2 J (2*26) lbs, of nitrogen per 
acre ; corresponding to about 1 1 lbs. of the " ammonia-salts," or 
to about 14^ lbs. of nitrate of soda. And, as illustrating how 
very great may be the loss when heavy rain and much drainage 
follow soon after the application of heavy dressings of ammonia- 
salts or nitrate of soda, it may be mentioned that one sample of 
drainage-water collected early in January 1872, after the appli- 
cation of GOO lbs. of ammonia-salts early in November, was 
found by Dr. Frankland to contain so much nitrogen as nitrates 
as to represent a loss of 18 lbs. of nitrogen per acre, correspond- 
ing to about 86 lbs. of the " ammonia-salts," or to about 114 lbs. 
of nitrate of soda, provided an inch of rain had passed away as 
drainage of that strength ; which, however, was probably not 
the case. Again, in one case of the Rothamsted analyses, the 
drainage-water collected on April 7th from the plot which had 
been dressed with 550 lbs. of nitrate of soda on March 10, con- 
tained so much nitrogen as nitrates as to represent a loss of 
about 15^ lbs. of nitrogen per acre, corresponding to about 
76 lbs. of the " ammonia-salts," or to about 100 lbs. of nitrate 
of soda, provided that (which again was probably not the case) 
an inch of rain had passed as drainage of that strength. 
It should be added that, besides nitrogen as nitrates and 
nitrites, land drainage-waters always contain more or less as am- 
monia or as organic nitrogen, but the quantity passing away in 
these forms is quite insignificant compared with that lost as 
nitrates. 
In consequence of the very conclusive evidence of the great 
loss by drainage of the nitrogen of ammonia-salts applied in the 
autumn, especially in wet winters, it was decided, in the autumn 
of 1872, to devote one plot in the experimental wheat field to 
the application of the ammonia-salts in the spring. Accord- 
ingly, plot 15, which had for many years been manured with 
approximately the same mineral manures, and approximately 
the same amount of nitrogen, as plot 7, was selected ; and, from 
that time, precisely the same mineral manures, and precisely the 
same amount of ammonia-salts were applied to plot 15 as to 
plot 7. To both plots the mineral manures were, as before, 
applied in the autumn ; to plot 7 (as to all the other ammonia- 
plots), the ammonia-salts also were applied in the autumn, but to 
