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. AEtheria, 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 B.C. to St. AEtheria in the latter part of the fourth century or later.  It includes books by trained writers, like Horace and Petronius, who consciously adopt the Latin of every-day life, and productions by uneducated people, like St. AEtheria and the writers of epitaphs, who have unwittingly used it.

St. Jerome says somewhere of spoken Latin that “it changes constantly as you pass from one district to another, and from one period to another” (et ipsa Latinitas et regionibus cotidie mutatur et tempore).  If he had added that it varies with circumstances also, he would have included the three factors which have most to do in influencing the development of any spoken language.  We are made aware of the changes which time has brought about in colloquial English when we compare the conversations in Fielding with those in a present-day novel.  When a spoken language is judged by the standard of the corresponding literary medium, in some of its aspects it proves to be conservative, in others progressive.  It shows its conservative tendency by retaining many words and phrases which have passed out of literary use.  The English of the Biglow Papers, when compared with the literary