Pliny: Natural History, Vol. V

that we have specified like shade and even cold.
Consequently the best course is to rely on experiment.

Soils favourable for trees, vines, and crops. XVI. 74.

III. It comes next after the heavens to give an
account of the earth, a subject no easier to deal with,
inasmuch as the same land is not as a rule suited for
trees and for crops, and the black earth of the kind
that exists in Campania is not the best soil for vines
everywhere, nor is a soil that emits thin clouds of
vapour, nor the red earth that many writers have
praised. The chalky soil in the territory of Alba
Pompeia and a clay soil are preferred to all the other
kinds for vines, although they are very rich, a quality
to which exception is made in the case of that class of
plants. Conversely the white sand in the Ticino dis-
trict, and the black sand found in many places, and
likewise red sand, even when intermingled with rich
soil, are unproductive. The signs adduced in judging
soil are often misleading. A soil in which lofty trees
do brilliantly is not invariably favourable except for
those trees: for what tree grows higher than a silver fir?
yet what other tree could have lived in the same
place? Nor do luxuriant pastures always indicate a
rich soil: for what is more famous than the pastures of
Germany? but immediately underneath a very thin
skin of turf there is sand. And land where plants grow
high is not always damp, any more, I protest, than
soil that sticks to the fingers is always rich—a fact that
is proved in the case of clay soils. In point of fact no
soil when put back into the holes out of which it is dug
completely fills them, so as to make it possible to
detect a close soil and a loose soil in this manner;
and all soil covers iron with rust.The writer is here contradicting Virgil, who says in Georgics II. 217-237 that a steamy soil which sucks up moisture and is always covered with grass, and which does not make iron rust, is good for vines trained up elm-trees, for olives, and for grazing and ploughland; and as a method of testing the quality of the soil he suggests digging a hole and then filling it in again, when if the earth does not completely fill the hole the land will be suitable for grazing and for vineyards, but if it more than fills it the soil will do for heavy arable land. Nor can a heavy