There was a public sanitary service and other Government employments which demanded properly instructed doctors in ancient Rome, and the practice of specialism in the treatment of disease was carried to even greater lengths than at present. Martial satirises this.[446] In the time of Strabo and in that of Trajan there were public medical officers in Gaul, Asia Minor, and in Latium. In Rome there were district medical officers for every part of the city. They were permitted to engage in private practice, but were compelled to attend the poor gratuitously. Their salary, according to Puschmann,[447] was paid chiefly in articles of natural produce. The _archiatri populares_ were the district physicians. The court physicians were called _archiatri palatini_. The _archiatri municipales_ were municipal physicians. Their guild was the COLLEGIUM ARCHIATRORUM, which in constitution was not unlike our Royal College of Physicians. Different societies employed doctors; the theatres, gladiators, and the circus retained surgeons. The art of ophthalmic surgery first became a separate branch of the medical profession in the city of Alexandria. Celsus states that PHILOXENUS, who lived two hundred and seventy years before Christ, was the most celebrated of the Alexandrian oculists.[448] Oculists were a numerous but ignorant class of practitioners in ancient Rome; their treatment was almost always by salves, each eye-doctor having his own specialty. Nearly two hundred seals with the proprietors’ names have been discovered which have been attached to the pots containing the ointments. Galen speaks contemptuously of the science of the eye-doctors of his time. Martial satirises them. “Now you are a gladiator who once were an ophthalmist; you did as a doctor what you do as a gladiator.” In another epigram he says, “The blear-eyed Hylas would have paid you sixpence, O Quintus; one eye is gone, he will still pay threepence; make haste and take it, brief is your chance, when he is blind he will pay you nothing.” Under Nero, DEMOSTHENES PHILALETHES, the famous doctor of Marseilles, was a celebrated oculist, whose work on eye diseases was the chief authority on the subject until about A.D. 1000. Paulus Ægineta, in his treatise on Ophthalmology, recommends crocodile’s dung in opacity of the cornea, and bed-bugs’ and frogs’ blood in trichiasis; yet with all this absurdity he distinguished between cataract and amaurosis. The ophthalmological literature of the Greeks and Romans has for the most part perished. Puschmann says that this branch of surgery must have been able to show remarkable results. “Not only trichiasis, hypopyon, leucoma, lachrymal fistula, and other affections of the external parts of the eye were subjected to operative treatment, but even cataract itself.”[449]