is obvious, that such as can be the most fully 
acted upon, and the most readily converted 
into the states suitable for affording the nu- 
trition of vegetables, by the principles of the 
matters thus employed as manures, must be 
the most adapted for the purpose, as well as 
the most beneficial. When, therefore, toe 
manure made use of in this way is either 
wholly or principally constituted of such ani- 
nialized matters, as from their fluidity are in 
an improper state or condition to be set on 
land without having other substances pre- 
viously mixed with them, such peaty, boggy, 
or black vegetable earths should be chosen as 
contain large proportions ot matter, which 
the ammonia or volatile alkali so abundantly 
provided by the decomposition of such sub- 
stances may exert itseif upon, and reduce 
into that state of solubility which is suitable 
for promoting the growth of plants. 
The results of experiments attentively 
made in this wav, indeed, clearly demonstrate 
that an inconceivable loss is incurred by the 
inconsiderate practice of exhccating human 
excrement, as well as the negligent custom 
of permitting the gaseous or liquid parts of 
dung heaps to evaporate or run away. I he 
trials which we have been enabled to make 
also lead us to suspect that it is a much more 
wasteful practice to apply these liquors to 
ground in their uncombined state, than in 
conjunction with such earthy materials as 
have been mentioned above. Besides, much 
of them must be imperceptibly carried off by 
the process of evaporation, even when they 
are carried out in the most favourable sea- 
sons of the year; and they cannot in this way 
always be made use of on those soils that 
contain a sufficient quantity of those earthy 
materials or principles with which they can 
readily form combinations, and exert their 
mo t beneficial and fullest effects. It may 
be demonstrated, by experiment, that yard 
and stable dung should be applied to the land 
in its half decomposed state, and not be suf- 
fered to remain in heaps until the putrefac- 
tive fermentation has reduced it to over pu- 
tridity. 
We are decidedly of opinion, that the soil 
of privies is a manure of the most enriching 
kind, but that its effects are not so lasting as 
those of many other substances. In some 
trials which have been lately made with it, it 
has produced such astonishing fertility, as in- 
duces us to conclude that it exceeds all other 
sorts of manure that can be put in competi- 
tion with it for the first year after its applica- 
tion. The second is of some service, but in 
the third its effects nearly, if not quite, disap - 
pear. The circumstances which render this 
sort of manure so immediately active in pro- 
moting vegetation, and so quickly deprived 
of' its beneficial iniiuence, would seem to be 
from the great quantity of elastic principles 
which it contains in a loose state of combina- 
tion, and the small quantity of earthy mattei 
which it is capable of supplying to the soil, 
by the last stages of decomposition or decay. 
‘This view of the nature of the manures 
afforded by different animals, should lead the 
practical agricultor to be more attentive to 
the subject, in order that he may render them 
more abundant, and be capable ot employ ing 
them under the most favourable circum- 
stances, which cannot be the case while they 
are, as at present, indiscriminately mixed and 
blended in the common dung-heap. 
HUSBANDRY. 
It is, however, from the larger animals that 
the farmer derives the principal part of the 
dung that is made use ot as manure, in the 
cultivation and improvement of land. The 
dung of such horses as are highly fed being 
found, as has been already seen, to be much 
more valuable for the general purposes ot 
agriculture, and some uses in horticultuie, 
than that which is made by horses when ted 
with hay or grass only. Where the animals 
are kept in the latter way, it is probably not 
so good as that of well-fed cows and neat 
cattle in general, as in these it may, perhaps, 
become more annualized from the circum- 
stance of their food being more intimately 
blended with the saliva, or other juices, dur- 
ing the ruminant state of feeding in such ani- 
mals. The dung of horses is, however, in 
common much more disposed to the pro- 
cess of putrefaction, and cause more heat, 
than that of cows and other neat cattle ; and 
indeed. these are the chief distinguishing cir- 
cumstances between them as manures. 1 he 
dung of neat cattle may also, on account of 
its less disposition to run into the state of pu- 
trefaction, contribute more of the earthy ma- 
terial to the land on which it is applied. 
Hence, probably 7 , its superior utility on the 
leaner and poorer or thinner sorts of soil. 
The dung and urine of animals when newly 
voided are not, except when the animals are 
morbid, in a putrescent condition, the length 
of time in which they 7 remain in their bodies 
being too short for its fully taking place ; but 
some degree of, or tendency to, putridity is 
constantly necessary to their discharge. 
From the experiments that have been 
made with the dung of sheep, it is evident that 
it is equally valuable with that of many 7 other 
animals that feed in the same way, but agri- 
culturists have not yet turned their attention 
sufficiently to the 'means of collecting and 
preserving it, so that it may be used alone as 
a manure. The method by which it is at 
present applied to land is by folding the ani- 
mals upon it, under which method of ma- 
nagement, on many soils, a great part of the 
advantage must be derived from the opera- 
tion or action of the ammonia of their urine 
upon the vegetable matters contained in 
them, as well as from the consolidation pro- 
duced by their treading. It is well known 
that the urine and dung of sheep want no fer- 
mentation previous to its being applied to the 
land; the sooner therefore the seed is sown 
after folding, the greater is the effect. 
Vegetable, as well as animal substances, 
when°deprived of their vital principle or life, 
are soon rendered fit, by the separation, re- 
duction, and ultimate decomposition, of their 
constituent principles, for tire nourishment 
and support ot new plants. r I his process is 
greatly 7 promoted, in ail kinds of substances, 
by the materials being exposed to the free in- 
fluence or agency of atmospheric air, mois- 
ture, and a middlihg degree of heat ; various 
matters are set at liberty, by which different 
new combinations take place, that are capable 
of promoting vegetation in different degrees, 
and upon which their utility as manures, per- 
haps, chiefly depends, 'ihe stages of this 
decomposition have generally been supposed 
to regularly succeed one another, from that 
which is productive of sweetness, through the 
vinous and acetous, to that which is the ulti- 
mate result of putrefaction. Different sorts 
and parts of organised matters, when dead, 
’ 6 C3 
939 
undergo many different sorts of chemical 
changes, which are different according to the 
degrees of heat, the quantity of water, and ot 
air, to which they are exposed. 
In the vinous fermentation or process which 
commences after the saccharine, carbon be- 
comes united with pure air in a large propor- 
tion ; and it is probable that, at the moment 
of their combination, while they are in the 
form of a liquid, and before they assume the 
gaseous state, they may be taken up by the 
roots of vegetables. 
The substances of the vegetable kind that 
may be advantageously converted into ma- 
nure are so extremely numerous, that it is 
impossible within our limits to describe them. 
All kinds of green vegetable productions may 
be employed in this way ; such as the luxu- 
riant weeds of rivers, lakes, ponds, and 
ditches; fern, and the refuse ot different 
kinds of garden vegetables. Where green 
materials ot this nature are made use of, they' 
should always be cut down while in their 
juicy state, 'just before their flowers begin to 
appear, in order that they may be in the most 
suitable condition for becoming quickly pu- 
trid, and to prevent the injury that might 
otherwise be sustained from the vegetation of 
their seeds. They are afterwards to be col- 
lected into heaps of a moderate size, and 
their putrefaction promoted by 7 their being 
thrown together as lightly as possible, and the 
occasional sprinkling of them with water, if 
the season be hot and dry ; and as lane is 
found, when applied to vegetables in their 
green moist state, to disengage from them 
both hydrogen and azote, by the combina- 
tion of which volatile alkali is produced, it 
may be advantageous to blend a portion of 
lime at first with the heaps, and afterwards 
add a suitable quantity of peat earth, or good 
vegetable moutd, for the alkali thus formed 
to act upon. By this method, the quantity 
of manure from such substances may be 
greatly augmented, and rendered more valu- 
able. ' But when dry materials, such as hay, 
straw of different kinds, fern, and rushes, 
such additions cannot be had recourse to 
with equal success, unless where much of the 
dung and urine of animals have been incor- 
porated with them; but their resolution and 
decay may be greatly promoted by their 
being kept in a state ot moisture, without the 
water being suffered to stagnate upon them, 
and by their not being permitted to be trodden 
down' too much by cattle, or other means, in 
the farm yards. 
Another beneficial means of vegetable ma- 
nure, which is yet far from being sufficiently 
practised, is that of providing full crops of 
succulent green vegetables, such as clover* 
buck-wheat, tares, vetches, spurry, pease, 
beans, turnips, and many other similar plants, 
to be turned down by the plough, in order 
that they may undergo the putrefactive pro- 
cess under the ground, and by that means be 
converted into manure, and supply the nu- 
trition of plants. 
Sea-weed is another vegetable production 
which is capable of being employed as a ma- 
nure with great advantage, and should never 
be neglected where it is within the reach of 
the farmer. In some places it is the practice 
to spread it upon the lands as soon as possible 
after being cut from the verges of the rocks 
on. tfee different sea coasts, or collected after 
