382 
On the Cultivation of OrcJtards, and 
pose. Nor is the opinion above entertained merely speculative, 
for we have almost everywhere sufficient jiroof that soils not 
naturally adapted to the growth of apples are, by the application 
of manure, made to produce them in great plenty and perfection. 
It cannot be denied that the ammonia, and also the humus of 
the decaying dung, must have some influence on the growth of 
the tree in such soils, and also on the development of the fruit;* 
but it is at the same time most certain that these alone would be 
perfectly inefficient for the production of the fruit without the co- 
operation of those bases which the manure also supplies, and which 
are naturally deficient in such soils as we are now speaking of. 
The size, and perhaps the flavour, of the fruit may be somewhat 
affected by the organic part of the manure, but its very existence 
depends upon the presence in the soil of a sufficient quantity of 
those inorganic or mineral substances which are indispensable to 
the formation of the acids. If further proof be wanting of the 
effect of potash upon the productiveness of fruit-bearing trees, it 
is to be found in the benefit derived from manuring apple-trees 
I with leaves which contain it in considerable quantity. This effect 
is remarkably exemplified in the application of the cuttings of 
vines to their roots, by which practice vineyards are kept in full 
bearing for any number of years, without any other manure, and 
of which Professor Liebig, in his admirable work on agricultural 
chemistry, has cited two remarkable instances. With these views, 
it is reasonable to refer the more general cultivation and preva- 
lence of orchards in the districts above named than in any other, 
principally to the greater abundance of that mineral food so 
essential to fruit-bearing trees, producing a large quantity of 
acid. We shall have occasion to revert to this subject in treating 
of the manuring of orchards. 
With regard to aspect, the districts above mentioned as being 
favourable to orchards have more or less an undulating surface 
(and therefore present numerous localities whose sheltered and at 
the same time sunny aspects are favourable both to the setting 
and ripening of the fruit), and often acclivities, which, though of 
excellent soil, are too steep either for cultivation or the pasture of 
heavy cattle. Very open or elevated and exposed situations, and 
the bottoms of deep-sunk valleys, are almost equally unfavour- 
able : the first from the violence of winds and low temperature, 
and the latter from their liability to cold fogs and late frosts 
while the trees are in blossom, which often, in one fatal night, 
utterly destroy the hopes of the husbandman. In planting an 
orchard, therefore, the site should not be chosen " in lowly vale 
* It is not probable that trees with large systems of leaves can be much 
indebted to the soil for those organic substances which the atmosphere so 
abundantly supplies. 
