[2831] A rich black mould, probably.
[2832] A ferruginous argilla.
[2833] It must of necessity denote a soil rich in humus, though not, of course, adapted for all kinds of cultivation.
[2834] He alludes to the difficulty with which argilla, from its tenacity, is employed in cultivation.
[2835] Columella says the contrary, and so does Virgil, Georg. ii. 226, speaking of this fact as a method of ascertaining the respective qualities of the earth.
[2836] Virgil, Georg. ii. 220, says the contrary.
[2837] In allusion to what Virgil says, Georg. ii. 254:—
“Quæ gravis est, ipso tacitam se pondere prodit,
Quæque levis——”
Fée remarks, however, that it is easy enough to analyse the earth, and ascertain the proportions of humus, and of the siliceous, cretaceous, or argillaceous earths; the relative proportions of which render it strong or light, as the case may be.