on Permanent Meadoiv Land. 
399 
the kind of manure employed. The proportions respectively of 
the Graminaceous, the Leguminous, and the other herbage, varied 
very considerably ; so also did the kind and amount of the several 
plants comprised within each of these main divisions; and so also 
did the proportions of leaf, stem, and seed, and the condition of 
maturity. 
Now the Leguminous herbage generally contains about twice 
as high a percentage of nitrogen as the Graminaceous. It also 
varies in composition in other respects. Leaves, stems, and 
seeds, differ much in composition from one another. And again, 
the degree of maturity of vegetable produce very much affects its 
percentage amount of certain important constituents. It will be 
obvious, therefore, that the composition of the complex produce 
— haz/ — must vary very considerably when grown by different 
manures. 
The object of this Fourth and last Part of our Paper is to show 
the variation according to season, and manuring, in the composi- 
tion of the hay grown on the different experimental plots, the par- 
ticulars of the manuring and produce of which have already been 
so fully considered in other points of view. 
In each of the three seasons over which the experiments have 
extended, the percentage amounts of total dry substance, of mineral 
matter, and of nitrogen, have been determined in the produce 
from each of the separate plots. The woody fibre has been deter- 
mined in the produce of each of the three years of those plots, 
which, in 1858, were selected for the botanical separations 
described in Part III. The fatty matter has been estimated in 
the produce of the same plots, but in that of the third season 
(1858) only. Lastly, complete analyses of the ashes of the produce 
of five out of the seven plots selecied for the botanical separa- 
tions, and also of the mixed ash of the produce from all the plots, 
for each of the three years separately, have been made. The 
various analytical results will now be considered under separate 
heads. 
Dry Matter. 
From each of the experimental plots, at the time the hay was 
carted, a sackful was taken, the samples being gathered from 
many parts of it. The whole of each of the specimens so taken 
was then cut into chaff and well mixed. From the mixed 
sample in this condition two quantities of 25 ounces each were 
weighed, and in both of these the dry matter and the mineral 
matter were determined. Other samples were at the same time 
taken for the determinations of nitrogen, woody fibre, &c. 
The dry matter, which alone is at present under consideration, 
was determined by submitting the duplicate 25-ounce samples, 
