, 
climate. In Flanders, where great quantities of 
flax are grown, the seed must be brought from 
the Baltic; otherwise the crop will be deficient. 
In the case of potatoes, also, seed is imported 
from an inferior climate, as the most likely 
means of preventing the disease called the curl. 
Besides changing seed, crossing different varie- 
ties has been found of use. Mr. Knight not only 
raised new varieties of apples, and of the garden 
pea, but likewise tried experiments with cross- 
ing wheat, which he effected by sowing the dif- 
ferent kinds together. ‘This was attended with 
a most extraordinary result; for when, in the 
year 1796, almost the whole crops of corn in the 
island were blighted, the varieties obtained by 
crossing alone escaped, though sown in different 
soils and in very different situations.” 
The quantity of any kind of agricultural or 
horticultural seed sown ought to be controlled 
by considerations respecting the climate, the soil, 
the season, the weather, the mode of sowing, and 
the quality of the seed. Ina climate of compa- 
rative unsteadiness and severity, which is liable 
to a succession of variable weather, or which is 
occasionally swept with great storms of rain or 
snow, or which is sometimes visited with unsea- 
sonable frosts or with great and sudden changes 
of temperature, a larger quantity of seed is re- 
quisite, were it merely to provide against acci- 
dental injuries and killings of the seed itself or 
of the young plants rising from it, than in a cli- 
mate of comparative repose and mildness. On 
thin light soils, which are favourable to tillering, 
and yet contain comparatively little sustenance 
for plants, and are unable to produce very luxu- 
riant crops, considerably less seed is proper than 
on strong, stiff, retentive soils, which are unfa- 
vourable to tillering, and yet’ contain compara- 
tively large stores of nourishment, and are well 
able to support the most abundant crops. But 
when even strong clay lands have been thoroughly 
under-drained, and are in high condition, and 
have been rendered friable and mellow by assidu- 
ous tillage and fallowing, they require as little 
seed as light lands, and sometimes even less. 
Though a sparcely sown crop of wheat, on such 
soils, may appear thin during winter, the seed- 
ling plants have time and vigour enough to fill 
up the field by means of tillering, and will be 
found to produce a full crop in autumn. When 
sown too thick, rich fields are apt to become 
overstocked with more plants than can come to 
perfection; and these accordingly grow up weak, 
slender, and unproductive. Less seed is required 
by summer fallowed land than by bean stubble, and 
less by bean stubble than by clover lea, and less by 
clover lea than by turnip land sown in spring. 
Seed sown at a comparatively remote period 
from the time of ripening gives the crop more 
scope for tillering and ampler power to overcome 
retardations and resistances from adverse wea- 
ther, than seed sown at a later period, and there- 
fore ought to be correspondingly less in quantity. 
SEED. 
169 
When the season is very dry, and occasions great 
paucity of moisture in the soil at the time of 
sowing, more seed may fail to vegetate than in 
other circumstances, and therefore proportion- 
ally more ought to be sown. Less seed is proper 
in the dibbling method of sowing than in the 
drill method, less in the drill method than in the 
broadcast method, and very much less in com- 
mixation with another seed for an accompanying 
crop than when sown alone and intended to oc- 
cupy the whole ground. Less quantity, too, is 
required of perfectly sound seed than of merely 
mediumly good seed, less of mediumly good seed 
than of very doubtful or decidedly bad seed, less 
of round, plump, large seed than of longish, slen- 
der, and comparatively bad seed, and less of seed 
which is well fortified by preparatory processes 
for resisting the attacks of insects and fungi and 
unfavourable weather than of seed of the same 
quality which is either not at all or very inade- 
quately fortified by such processes. See the 
article SowinG. 
The preparing of seeds comprises processes for 
detecting and separating unsound grains,—pro- | 
cesses for accelerating germination or promoting 
earliness of growth after sowing,—processes for 
protecting the seeds against the attacks of ver- 
min, grubs, and parasites,—and processes for | 
>) y) y) 
augmenting the nutrimental resources of the 
seeds, and enabling them either to dispense, in 
some degree, with the aid of manures in the 
soil, or to use up the manures with a more luxu- 
riant and productive account. One of the sim- 
plest of these processes is noticed in the article 
Brinine; and some of the most peculiar are 
mentioned in the articles on the several plants 
or crops to which they apply. 
The detecting and separating of unsound grains 
can, in most instances, be readily accomplished 
by merely pouring the seeds gently into common 
water or into a weak solution of salt and water, 
—and, if necessary, slightly stirring the water or 
solution till all the grains have an opportunity 
of becoming immersed or wetted; for the sound 
grains will sink to the bottom and remain 
there, and the unsound ones will either swim 
from the first on the surface or will readily rise 
with aslight stirring, and may easily be skimmed 
off. 
The accelerating of the germination of seeds is 
generally effected by artificial applications of 
heat and moisture during some hours or days 
immediately before the intended time of sowing. 
A common method is simply to steep the larger 
and clean-skinned seeds, such as beans and barley, 
in pure water, and to immerse the smaller and 
rougher seeds, such as those of carrots, in a little 
well-moistened soil, and to keep it in a warmish 
place, and turn it occasionally over. But all 
such processes, especially in the case of the for- 
mer class of seeds, require to be conducted with 
judgment and caution and a wise regard to time 
and temperature ; for, if otherwise conducted, 
