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-be separated and kept by itself. 
RAPE CAKE. 
the admission of any kind of air. If the cakes be 
new, they will heat a little; and if they have not 
had a due ‘sweat’ in the ship, or may be appre- 
hended to be more than usually prone to heat, 
the broken and pulverized portion of them should 
Both the dealer 
and the large consumer who keep a quantity of 
rape in the shape of dust by them, ought never 
to fling it down in the corner of a cart-shed, or 
in any similar place, where it is exposed to the 
humidity of the air, and to the interference of 
| pigs and poultry. 
However dry it may appear, 
and however free from liquid moisture it may be 
_ kept, yet, on being laid somewhat thick together, 
_ it will sooner or later heat, and may eventually 
_ form a large portion of its substance into lumps 
_as black as soot and not much different in in- 
ternal appearance from coal cinders. Any heap 
of rape dust which threatens to become heated, 
should be spread as thin as the space for it will 
_ permit, and now and then turned carefully over. 
A chief value of rape dust as a manure depends 
on its comparatively large proportion of nitrogen, 
and consists partly in the contribution which that 
element makes to the feeding of a crop, and partly 
in the readiness with which it sets up decompo- 
sition, and generates heat, and communicates 
the fermentative action to other dead organic sub- 
stances which are more reluctant to decay. Ac- 
cording to analyses by Boussingault and Payen, 
normal cole-cake contains 4°92 per cent. of nitro- 
gen, while normal farm-yard manure contains 
only 0'4 per cent.; so that, in everything which 
depends on the action of nitrogen, 8°13 cwts. of 
cole-cake ought to manure as much land as 5 
tons of farm-yard manure. But rape-cake also 
exerts very considerable manurial power, both 
by contributing earthy phosphates in direct nu- 
trition to crops, and by combining the action of 
various saline and organic principles in the fer- 
mentative process within the soil. According to 
a testing process by Dr. Madden, 100 parts of 
rape-dust dried at 212° Fahrenheit give off 10:5 
parts of water; and of the remainder, 24°7 are 
soluble in cold water, 4°8 are soluble in hot water, 
31°5 are soluble in weak potash, 10-2 are soluble 
in strong potash, 14:3 are destroyed by heat, 3:0 
consist of earthy phosphates, and 1°0 consists of 
silicate of potash. 
Mr. Hannam, in his Prize Essay on Rape Dust 
and other Hand-Tillages, states, as practical con- 
clusions from his own experience, that rape-dust 
produces its most marked effects on thin poor 
soils,—that it operates more beneficially in a dry 
season than in a moist one,—that it is most cer- 
tain in its effects upon winter-sown wheat-crops, 
but, in favourable seasons, most remunerative on 
the spring crops,—that it answers best on strong 
soils for wheat-crops,—that it cannot judiciously 
be applied in large quantities at one time,—and 
that, when used for several rotations, it requires 
to be followed by a top-dressing of saline and 
earthy matters. Most practical writers, however, | 
say that it does better on moist soils than on 
dry ones, and better on any land in wet seasons 
than in dry ones ; and the truth may be that it 
does best in its proper or unmixed state on dry 
soils and in dry seasons, and best in a state of 
large dilution or controlling intermixture with 
other substances on moist soils and in wet sea- 
sons. Its valuable and powerful tendency to set 
up or accelerate decomposition in other sub- 
stances requires that it be mixed with them, and 
is mightily aided by the presence of moisture; 
and this very tendency, at the same time, en- 
dangers the killing and rotting of the crop-seeds, 
if it be deposited in direct or undiluted contact 
with them, and may, in that case, be rendered 
mild and innocuous by the comparative absence 
of moisture. It also decomposes too rapidly, and 
becomes wastefully dissipated, when subjected 
unmixedly to the action of moisture; so that, 
whenever it is applied to moist land, or likely to 
be exposed to moist seasons, it should either be 
combined with some other and far bulkier or- 
ganic manure, or largely diluted with an inter- 
mixture of ashes or of some dry porous earth. 
It may be used likewise to strengthen a liquid 
manure with an urine basis, to modify and enrich 
an excessively ammoniacal liquid manure, to 
form an artificial liquid manure by solution in 
water with the addition of some urine, and to 
set up decomposition with great speed and with 
highly fertilizing result in a compost of peat or 
of any other inert vegetable substance. In most 
modes of application, it is supposed to be de- 
structive to the majority of insects which infest 
the soil; and, in mixture with elder or worm- 
wood, in particular, it is thought to be an anti- 
dote against the wireworm. 
Rape-cake is commonly reduced to powder in 
a one-horse mill at the rate of 5 tons a-day. The 
dust or powder is applied either in the drill, or 
in broadcast sowing, or in the way of top-dress- 
ing; and it is commonly given at the rate of 
from 10 to 15 cwt. per acre for turnips, and at 
from 10 to 12 cwt. or less for clover or grass or 
grain crops. When applied in the drill, method 
to wheat, it does best to be partly given at the 
time of sowing in autumn, and partly drilled 
into the spaces between the rows in March and 
April,—for if given wholly in autumn, it is apt 
to make the plants grow too strong and root- 
fallen ; and when applied in the broadcast me- 
thod, it requires merely to be sown and harrowed 
in with the seed of grain crops, or to be sown on 
grass or on the braird of grain without harrow- 
ing. But when diffused over the surface as a 
top-dressing, a great portion of it is wastefully 
dissipated in gaseous products of decomposition, 
some is carried off by birds, and more or less is 
appropriated by weeds. Its proper use as a main 
ingredient in liquid manure is somewhat pecu- 
liar. “It is probable,” says Mr. Rham, “ that 
the most advantageous mode of using it on the 
land, after it has been dissolved in the urine 
