Unmindful of a kindness.

The sort of kindness one is least likely to forget is that which our master used to say he conferred upon us, when he was inculcating learning by means of the rod. We cannot help thinking, however, that he began at the wrong end.

Imperitus rerum:

Unacquainted with the world, i.e. Not ‘up to snuff’.

Much controversy has been wasted in attempts to determine the origin of the phrase “up to snuff”. Some have contended that it was suggested by the well-known quality possessed by snuff, of clearing the head; but this idea is far fetched, not to say absurd. Others will have that the expression was derived from Snofe, or Snoffe, the name of a cunning rogue who flourished about the time of the first crusade; so that “up to Snoffe” signified as clever, or knowing, as Snoffe; and was in process of time converted into “up to snuff.” This opinion is deserving of notice; though the only argument in its favour is, that the phrase in question was in vogue long before the discovery of tobacco. Probably the soundest view is that which connects it with the proper name Znoufe, which in ancient High-Dutch is equivalent to Mercury, whose reputation for astuteness among the ancients was exceedingly great. Conf. Hookey-Walk, ii. 13. Hok. Pok. Wonk-Fum. viii. 24. Cheek. Marin. passim, with a host of commentators, ancient and modern.

Roscius timidus Deorum fuit:

Roscius was afraid of the Gods.

Adjectives ending in ax, derived from verbs, also require a genitive case, as

Tempus edax rerum:

Time is the consumer of all things.