42 
ON CHEMISTRY. 
than that it should he carried too far ”—“ The excess of fermentation 
tends to the destruction and dissipation of the most useful part of the 
manure; and the ultimate results of this process are like those of 
combustion.” —Davy. 
For the purposes of the farm, the medium state adopted by Mr. 
Coke, appears to be in every way preferable. He forms his mixens, 
by layers of the several products of the cow-yard and byre, piggery, 
and stable : presses the heaps as much as possible, by carting over 
them, and then covers the whole with a slight stratum of earth to re¬ 
tard the fermentation. 
The heaps are formed in winter, and remain thus, till within two 
or three weeks of turnip sowing; they are then turned over, and im¬ 
mediately carted to the fields. 
For the Garden , where any superficial dressing is required to pro¬ 
duce immediate effect, perfectly rotted manure, or good spit dung, is 
most eligible; but the most economical process for works, on the 
large scale, and for permanent crops, would be effected by deep 
trenching with the spade, and burying perfectly recent farm yard 
and stable dung, to the extent of four or six inches at the bottom of 
each trench, sprinkling the surface of the dung with Carbonate of 
Soda, or common Salt. Decayed manure might be dug in with the 
surface soil; and thus the ground would be enriched for first crops, 
and be in a state to receive, gradually, the gaseous products of fer¬ 
mentation from beneath, after a season or two, trenching would bring 
up the solid remains of the dung, and intermediately, nothing would 
be lost. 
By a similar process, I have produced carrots and parsnips so 
much superior to those generally grown near me, that they have 
been admired by all who have seen them. 
Decomposition produces attraction; the decomposing material 
ought, therefore, to be so situated as to produce the desired effect. 
Tap-rooted vegetables require a deeply deposited substance, which, by 
its local attractive energy may induce perpendicular descent. Potatoes 
and tuberous roots, require lateral attraction ; hence, the manure 
should be generally extended throughout the surface-spit of each. 
Fibrous rooted plants ought to find decomposable matter in every 
direction; and fruit trees should be supplied from above, to prevent 
deep-rooting, and to secure the lateral and almost superficial exten¬ 
sion of the roots. Such are, I believe, the general principles which 
every gardener might safely keep in view, and observe as the ground 
of his practice. 
But how do Manures act P The solution of this question involves 
