employment for
many intelligent Romans; and every part of the empire seems to have been
filled with cultivated men, who, possessing wealth and leisure, gave
themselves to literary studies. Aulus Gellius, one of the best known of
the grammarians, lived during the period of the Antonines. His _Noctes
Atticae_ is a critical work in twenty books, in which he discusses many
questions in language, philosophy, and science. He seems to have passed
his life in traveling over Italy and Greece, collecting materials for
this work, and, wherever he goes he never fails to meet with agreeable,
intelligent friends, who delight, like himself, in improving
conversation.

Aurelius Macrobius, another well-known grammarian, lived during the
fifth century. His Commentary on the Dream of Scipio is full of the
scientific speculations of his age. His _Saturnalia_ contains many
extracts from the best Roman writers, with criticisms upon them, in
which he detects the plagiarisms of Virgil, and observes the faults as
well as the beauties of the orators and poets of Rome. The works of
other grammarians have been preserved or are partly known to us, among
which are those of Servius, Festus, Priscianus, and Isidorus.

The study of the law, too, flourished in uncommon excellence under the
emperors, and nearly two thousand legal works were condensed in the
Digests of Justinian, few of which belonged to the Republican period.
Under Augustus and Tiberius, Q. Antistius Labeo founded the famous
school of the Proculians. He left four hundred volumes upon legal
subjects. His rival, C. Ateius Capito, founded the school of the
Sabinians, and was also a profuse writer. Under Hadrian, Salvius
Julianus prepared the _Edictum Perpetuum_, about the year A.D. 132,
which condensed all the edicts of former magistrates into a convenient
code. Papinianus, Ulpianus, and Paulus were also celebrated for their
legal writings. The only complete legal work, however, which we possess
from this period, is a Commentary by Gaius, who lived probably under
Hadrian. This valuable treatise was discovered in the year 1816 by the
historian Niebuhr, in the library of Verona. It contains a clear account
of the principles of the Roman law, and the Institutes of Justinian are
little more than a transcript of those of Gaius.

Various medical writers also belong to the Imperial period, the most
important of whom is A. Cornelius Celsus. Works on agriculture were also
written by Columella, Pa