ever, whether the system of valuation which is accurate in the case
of a guano or other rapidly acting substance, is applicable to farm-yard
manure, the effects of which extend over some years. A deduction must be
made for the years during which the manure remains unproductive, and
also for the additional expense incurred in carting and distributing a
substance so much more bulky than the so-called portable manures, and it
would not be safe to estimate its value at more than 7s. or 8s. per ton.

_Liquid Manure._--This term is applied to the urine of the animals fed
on the farm, and to the drainings from the manure-heap, which, in place
of being returned to it, are allowed to flow away, and collected in
tanks, from which they are distributed by a watering-cart, or according
to the method recently introduced in Ayrshire, and since adopted in
other places, by pipes laid under-ground in the fields, and through
which the manure is either pumped by steam-power, or, where the
necessary inclination can be obtained, is distributed by gravitation.
That liquid manure must necessarily be valuable, is an inference which
maybe at once drawn from the analyses of the urine of different animals
already given, and of which it chiefly consists. In addition to the
urine, however, it contains also the soluble organic and mineral matters
of the dung, as well as a quantity of solid matters in suspension, among
which phosphates are found, and thus it possesses a supply of an
element which would be almost entirely deficient if it were composed of
urine alone. In the following analyses by Professor Johnston, No. 1 is
the drainings of the manure-heap when exposed to rain; and No. 2 the
same, when moistened with cows' urine pumped over it, the results being
expressed in grains per gallon:--

No. 1. No. 2.
Ammonia 9.6 21.5
Organic matter 200.8 77.6
Ash 268.8 518.4
----- -----
Total solids in a gallon 479.2 617.5

The ash contained--

Alkaline salts 207.8 420.4
Phosphates 25.1 44.5
Carbonate of lime 18.2 31.1
Carbonate of magnesia, and loss 4.3 3.4
Silica and alumina 13.4 19.0
----- -----
268.8 518.4