a Latin writer (judging by his name) on Material Medica, who lived later than Cratevas, and a little before Dioscorides (Dioscor. De Mat. Med. i. praef., vol. i. p. 2), and therefore probably about the beginning of the first century after Christ. He seems to have enjoyed some reputation as a writer, as he is mentioned by St. Epiphanius (ad v. Haeres. 1.1. 3. p. 3), and several times by Galen among eminent pharmaceutical authors (De Simplic. Medicam. Temper. ac Fault. vi. praef. vol. xi. p. 797, De Antid. 1.2. vol. xiv. p. 7, Gloss. Hippocr. praef. vol. xix. p. 64). Caelius Aurelianus calls him the friend of Tullius Bassus (De Morb. Acut. 3.16. p. 233), and Galen says he was a follower of Asclepiades l.c. vol. xi. p. 794.). * That is, if in the passage in question for Τάνιτρον τοῦ Ἀσκληπιάδου we read τὰ Νιγρον τοῦ Ἀσκληπιαδείου. He is perhaps the person called Sextus Niger by Pliny (Index to H. N xx.), and some suppose his name to have been Petronius Niger. [PETRONIUS.]