496 
Iiifluence of Climate on Cultivation. 
than the climate. The feeding quality of turnips and grasses is 
greatly regulated by the inherent chemical nature of the soil, 
which apparently cannot be imitated artificially. Turnips, 
grasses, potatoes, grown on the black sands of Norfolk are 
all alike of poor quality. On the other hand, the red loams 
of Dunbar, in East Lothian, produce the finest potatoes that 
reach the London market : this is not owing to climate. It is 
the chemical qualities of these soils that impart a high feeding 
value to all kinds of roots and grasses that grow upon them. There 
are no marked differences in the mode of cultivating or manuring 
this crop in the British Islands, if we except the garden-like 
culture which is expended upon it in the south and western 
parts of England where early spring crops are raised. 
Lef/uminous Crops. — The increasing relative value of turnips 
and potatoes, and the fact of their being well adapted for pre- 
paring the soil for cereals, has had the effect of diminishing the 
extent of land under beans or peas. In Scotland, before the 
introduction of turnips, the pea was largely sown on the lighter 
descriptions of soil and the bean on the richest lands. The 
latter requires a soil possessing retentive .qualities for manure 
and moisture : it is injured by droughts of long continuance, 
and then becomes liable to the attacks of insects. For this 
reason it is a somewhat precarious crop in the south of England. 
Winter beans are less liable to be injured by drought, and grow 
more healthily. On the rich level plains of the Lothians the 
bean grows in great perfection. Its culture is usually much the 
same as that for potatoes or turnips : the ridges or drills arc 
27 inches apart, which admit of the crop being horse-hoed and 
otherwise thoroughly cultivated during its early growth. The 
English system of sowing in narrow drills of 18 inches has been 
recently tried in the Lothians and other parts with satisfactory 
results. Whether the advantages will hold in moist seasons, 
experiments still have to decide. The pea, on the other hand, 
can thrive in comparatively light soils, which seems to indicate 
that it evaporates less water than the bean, for it thrives in 
drier climates. The bean is no doubt susceptible of moisture 
during the blooming season, and then the flowers do not set well ; 
but the pea is still more so, and in such circumstances the 
perennial qualities are so much excited that it puts forth leaves 
until the frosts of winter check its growth. In moderately dry 
climates, where the summer heats are not too great, some varieties 
of peas throw out fresh leaves, blossoms, and fruit, for an 
extended period. These afford a good illustraticm of the prin- 
ciple that the latest varieties are the most productive. When the 
soil has been somewhat reduced in fertility, the early varieties of 
jieas do not bear well ; but under the same circumstances the late 
