Spanish, then, we can reconstruct a Latin formation current among the
common people. Finally a knowledge of the tendencies and practices of
spoken English helps us to identify similar usages when we come upon them
in our reading of Latin. When, for instance, the slave in a play of
Plautus says: "Do you catch on" (tenes?), "I'll touch the old man for a
loan" (tangam senem, etc.), or "I put it over him" (ei os sublevi) we
recognize specimens of Latin slang, because all of the metaphors involved
are in current use to-day. When one of the freedmen in Petronius remarks:
"You ought not to do a good turn to nobody" (neminem nihil boni facere
oportet) we see the same use of the double negative to which we are
accustomed in illiterate English. The rapid survey which we have just made
of the evidence bearing on the subject establishes beyond doubt the
existence of a form of speech among the Romans which cannot be identified
with literary Latin, but it has been held by some writers that the
material for the study of it is scanty. However, an impartial examination
of the facts ought not to lead one to this conclusion. On the Latin side
the material includes the comedies of Plautus and Terence, and the comic
fragments, the familiar odes of Catullus, the satires of Lucilius, Horace,
and Seneca, and here and there of Persius and Juvenal, the familiar
letters of Cicero, the romance of Petronius and that of Apuleius in part,
the Vulgate and some of the Christian fathers, the Journey to Jerusalem of
St. Ætheria, the glossaries, some technical books like Vitruvius and the
veterinary treatise of Chiron, and the private inscriptions, notably
epitaphs, the wall inscriptions of Pompeii, and the leaden tablets found
buried in the ground on which illiterate people wrote curses upon their
enemies.

It is clear that there has been preserved for the study of colloquial
Latin a very large body of material, coming from a great variety of
sources and running in point of time from Plautus in the third century