326 
MESSRS. J. B. LA WES AKD J. H. GILBERT OR THE RESULTS OF 
one slight exception, given more every year since, and in the latter half of the period 
very much more. But, besides any advantage from position and shade of plot 12 over 
plot 3, the examination of, and the determinations of nitrogen in, the subsoil of plot 12 
showed it to be much more mouldy and much richer than that of plot 3, and it was 
concluded that the plot consisted, in great part at any rate, of made or moved ground, 
the site possibly of a filled-up hollow, or of a removed and levelled plantation or hedge 
green. Neither the sections nor the analyses of the subsoil of plot 13 showed any 
such characters, however, so that, independently of manure, the only known difference 
between it and plot 9 was in its earlier afternoon shade. 
The herbage of plot 13 has become even more prominently gramineous than that of 
plot 9. Leguminosae have almost equally disappeared on both; and the Miscellanese 
have also greatly reduced on both, Rumex acetosa being the only very prominent weed 
on either, Conopodium denudatum coming next. The increase of produce on plot 13 
was, in fact, almost exclusively due to an increase in gramineous herbage, and this, 
compared with that of plot 9, contained very much more Dactylis g., which here 
becomes the most prominent species ; about the same proportion of Agrostis v., con¬ 
siderably less Holcus /., very much less of Festucci o., and especially of Poet prat. ; but, 
on the other hand, a fair proportion of Alopecurus p., which is scarcely represented on 
plot 9 ; whilst, Avena pub. and jiav ., and Poa triv. have gone down very much on both 
plots. Thus, compared with that of plot 9, the produce of plot 13 (with the straw) 
was somewhat differently made up, but it comprised a considerable proportion of 
several of the freer-growing grasses. These, too, manifested considerable tendency to 
form strong seed-stems. 
These characters indicate liberal nitrogenous and mineral supply within the soil, and 
as they predominated more on plot 13 than on plot 9, it would be supposed that these 
conditions prevailed on it the more. 
Supposing the whole of the nitrogen of the staw became available, it would supply 
about 9 lbs. per acre per annum, and presumably a smaller proportion of it at first, and 
more and more each year. Consistently with this, there was either no excess of yield 
of hay and of nitrogen, or but little, on plot 13 compared with plot 9, in the earlier 
years, but a considerable excess over the latter half of the period; and there was an 
increase of about 10 lbs. of nitrogen per acre per annum over the 20 years. It is 
probable, however, that, owing to various conditions favourable to luxuriance, the 
growing plants were enabled to avail themselves of more also of the other supplies of 
nitrogen within the soil. 
Of mineral matter, the crop of plot 13 took up, over the first 10 years rather more 
than 20 lbs., over the second 10 rather more than 80 lbs., and over the 20 years rather 
more than 50 lbs., per acre per annum, more than that of plot 9. There was some 
increase in the amounts taken up of all the mineral constituents, but the most marked 
was—of potass an average of about 23 lbs., of phosphoric acid about 4 lbs., and of 
chlorine about 8 lbs., with in each case more over the second period than the first. 
