The followers of Æsculapius, and the priests in the temples dedicated to him, soon formed a separate caste, transmitting from one to another, as a family heritage, their medical knowledge. At first no one was admitted to practice the sacred science unless lie joined the priesthood, although later this secrecy was relaxed. They initiated strangers, provided they fulfilled the test which they made. Some kind of medical instruction was given in each temple. The three most celebrated temples to Æsculapius were that of Rhodes, already extinct by the time of Hippocrates; that{009} of Cnidus, which published a small repertory; and finally that of Cos, most celebrated of all, because of the illustrious men who emanated from this school. In these temples votive tablets were fastened in large numbers, after the fashion of the Egyptians, the same giving the name of the patient, his affliction, and the manner of his cure. For example, such a one as this: "Julien vomited blood, and appeared lost beyond recovery. The oracle ordered him to take the pine-seeds from the altar, which they had three days mingled with honey; he did so, and was cured." [Illustration: 0029] Having solemnly thanked the god, he went away. There is reason to think that the priests of these temples made for their own uses much more minute and accurate accounts, which should be of some real service, since the writings which have come down to us evince a habit of close observation and clear description of disease. During the Trojan War{010} two men are frequently mentioned by Homer as possessing great surgical skill. These were _Machaon_ and _Podalirius_. They were regarded as sons of Æsculapius, the former being the elder. The first account of venesection, although not authentic, refers to the bleeding practiced by the latter upon the daughter of the King of Caria, upon whose shores Podalirius was cast by tempest after the ruin of Priam's kingdom. Whether he was the first of all men to practice it or not, it is certain that the act of venesection goes back long prior to the era of Hippocrates, who speaks of it as frequently performed. Many of the deities upon Olympus seem at one time or another to have usurped medical functions. Apollo, the reputed father of Æsculapius, appropriated nearly everything under the name of Pæon, who assumed the privilege of exciting or subduing epidemics. Juno was supposed to preside at accouchements, and in both the Iliad and Odyssey it is indicated that Apollo was considered as the cause of all the natural deaths among men, and Diana of those among women.