ARETÆUS OF CAPPADOCIA (1st cent, A.D.) was a celebrated Greek physician who wrote on diseases, detailing their symptoms with great accuracy and displaying great skill in diagnosis. He was very little biased by any peculiar opinions, and his observations on diseases and their treatment have stood the light of our modern medical science better than those of many of the ancient authorities. He was acquainted with the fact that injuries to the brain cause paralysis on the opposite side; and his classification of mental diseases is as good as our own. His knowledge of anatomy was considerable, and in his physiology he shows how much more the ancients knew of this branch of science than is generally supposed. He was acquainted with the operation of tracheotomy, and remarked its partial success.[493] He considered elephantiasis to be contagious, and gives this caution: “That it is not less dangerous to converse and live with persons affected with this distemper, than with those infected with the plague; because the contagion is communicated by the inspired air.”[494] HERODOTUS (there were several of the name) was a physician of repute in Rome (about A.D. 100). He was a pupil of Athenæus or Agathinus, and wrote several medical books which are quoted by Galen and Oribasius. He first recommended pomegranate root as a remedy for tape-worm, and described several infectious diseases.[495] HELIODORUS (about A.D. 100) was a famous surgeon, and wrote on amputations and injuries of the head. His operation for scrotal hernia is described by Haeser as “a brilliant example of the surgical skill of the Empire.” He treated stricture of the urethra by internal section. CASSIUS FELIX lived in the first century after Christ, and was the author of a curious set of eighty-four medical questions and their answers. He was also called CASSIUS IATROSOPHISTA. LEONIDAS of Alexandria lived in the second or third century after Christ, was a distinguished surgeon, who operated on strumous glands, and amputated by the flap operation.