344 Report of Experiments on the Growth of Barley, 
February 26, 1873, is higher than that in the winter drainage 
from the same plot examined by Dr. Voelcker, and adopted in 
the illustrations above given. 
It should be added that, even the? drainage from the plots 
manured exclusively with mineral manure and ammonia-salts or 
nitrate of soda would appear, according to Dr. Frankland's 
analyses, to contain nitrogen as ammonia and organic nitrogen, 
in amount averaging about 4 or 5 per cent, as much as that 
found as nitrates and nitrites, and by so much, therefore, in- 
creasing the loss of combined nitrogen by drainage, beyond that 
indicated by the quantity of nitrates and nitrites alone. In the 
drainage from the dunged plot, however, the amount of ammonia 
and organic nitrogen is, both actually, and relatively to the quan- 
tity as nitrates and nitrites, much more than in that from the 
artificially manured plots. 
From the foregoing considerations it seems extremely probable 
that the whole of the nitrogen applied to the wheat as ammonia- 
salts or nitrate of soda, was either recovered in the increase of 
the crop, accumulated within the soil, or lost by drainage. 
As the experimental barley-field is not artificially drained, 
we are unable to illustrate the point in the same manner in 
regard to ^e barley as to the wheat crop. It has, however, 
been conclusively shown that, in the case of the barley, a greater 
amount of increase is obtained for a given quantity of nitrogen in 
manure than in that of the wheat ; and that a larger proportion 
of the nitrogen supplied is recovered in the increase of produce 
within a given time. How are these facts to be explained ? 
From the facts adduced, it is clear that a material loss of 
nitrogen takes place by drainage in the winter, when ammonia- 
salts are applied in the autumn for the wheat crop ; and since 
the manures for the barley are not sown until the spring, all loss 
of the freshly-supplied nitrogen by winter rains is avoided. 
Further, not only would there be comparatively little drainage 
after the spring sowing, but growth being at once established, the 
nitrogen, whether applied in the form of ammonia or of nitrate, 
would be rapidly taken up. The analyses of the drainage 
from the wheat-field show that the water collected during the 
spring contained, compared with that of the winter, very little 
nitrogen. This is probably partly accounted for by the pre- 
vious washing out of the soil in the winter, but it is doubtless 
also in a great measure due to the action of the growing crop. 
It is only what would be expected, therefore, that a given quantity 
of ammonia-salts applied for barley in the spring, should yield 
a much better result than an equal amount applied for wheat 
in the autumn. 
Even in the wheat experiments, nitrate of soda has always 
