EXPERIMENTS ON THE MIXED HERBAGE OF PERMANENT MEADOW. 383 
and very much more chlorine, taken up with, than without, the ammonia-salts. Of 
sulphuric acid and chlorine there was, of course, a considerable quantity annually 
applied in the mixture of sulphate and muriate of ammonia used. Of potass, there 
was an increased amount taken up during the first eight years, actually rather less 
during the next six years, and very little more during the last six—in all, over the 20 
years, not 3 lbs. per acre per annum more taken up with, than without, the ammonia- 
salts. There was, however, over each period, very much more soda taken up with the 
ammonia-salts, and over the whole period there was nearly three tunes as great an 
increase of soda as there was of potass in the produce. Of silica, there was rather 
more taken up with ammonia than without it over the eight years of the application of 
the dung, but rather less subsequently, and over the 20 years all but identical amounts 
on both plots. 
It is obvious that the increased amounts of lime and magnesia, of potass and soda, 
and of phosphoric acid, taken up under the influence of the ammonia-salts, must have 
had their source in the previous supplies within the soil, or in the residue from the 
farmyard manure; and, so far, the action of the ammonia-salts has been more rapidly 
to utilize, and therefore the more to exhaust, these otherwise dormant stores. But, 
from the very slight increase in the amount of potass taken up, and the very much 
greater increase in that of soda, it may be concluded that there was a relative deficiency 
of available potass within the soil, notwithstanding the comparatively large amount 
probably supplied in the dung; in fact, the increased yield of potass over that without 
manure amounted, on both plots, to only about half that estimated to be supplied. It 
would appear that the residue of the potass of the dung, which we know to be but 
little subject to drainage, was nevertheless but slowly available to the succeeding crops. 
Of phosphoric acid, again, there was very much less increased amount taken up under 
the influence of the ammonia-salts than there was of either sulphuric acid or chlorine, 
both of which were so liberally supplied. It was probable that, of both the potass and 
the phosphoric acid supplied in the dung, part remains unliberated from its original 
condition of combination in the manure, and part becomes so locked up (or distributed) 
within the soil, as to be only very slowly available. 
Of nitrogen, there was a somewhat higher percentage in the dry substance of the 
produce with, than in that without, the application of ammonia-salts, but still less than 
in that without manure, which contained so much more leguminous and miscellaneous 
herbage. Of total mineral matter, there was a lower percentage with than without the 
ammonia-salts. Of magnesia and of sulphuric acid, but especially of soda and of 
chlorine, the percentage was higher in the dry substance of the hay grown with the 
ammonia-salts; but of lime, and of phosphoric acid, the percentage was less, and of 
potass and silica (especially in the later years) it was very much less, under the influence 
of the ammonia-salts. 
Upon the whole, the evidence goes to show that the effect of the ammonia-salts was 
