1239. (2.) The genitive with an adjective in agreement is used to denote
quality, either attributively or predicatively: as,
(_a._) Attributively: #magnī ponderis saxa#, 2, 29, 3, _stones of great
weight_. #summae speī adulēscentēs#, 7, 63, 9, _young men of high
promise_. #diērum vīgintī supplicātiō#, 4, 38, 5, _a twenty day
thanksgiving_. #bēlua multōrum es capitum#, H. _E._ 1, 1, 76,
_a many-headed beast art thou_. #eius modī cōnsilium#, 5, 29, 5, _such a
plan_. #dēmittō auriculās ut inīquae mentis asellus#, H. _S._ 1, 9, 20,
_I drop my ears like Neddy in the sulks_ (269). #vāllō pedum IX#, 5, 42,
1, _with a nine foot palisade_. (_b._) Predicatively: #magnae habitus
auctōritātis#, 7, 77, 3, _passing for a man of great influence_.
#flūminis erat altitūdō circiter pedum trium#, 2, 18, 3, _the depth of
the river was about three feet_. The genitive of quality resembles the
ablative of quality (1375); the two are sometimes combined: as, #hominem
maximī corporis terribilīque faciē#, N. 15, 4, 1, _a man of gigantic
frame and with an awe-inspiring presence_. But the genitive is common in
designations of size and number.
1240. A substantive expressing quality with #aequus#, #pār#, #similis#,
or #dissimilis# in agreement, is put not in the genitive, but in the
ablative, by Cicero, Caesar, Nepos, and Livy.