But besides this sacerdotal medicine, there was also a lay medicine in Greece. Many great philosophers, especially Pythagoras, Alcmeon of Croton, Empedocles, Anaxagoras, and Democritus, occupied themselves with physiology, with hygiene, and with medicine; also the gymnasiarchs, or directors of gymnasiums, or schools of gymnastics, an art having for its end to increase physical strength and maintain health, cultivated medicine, particularly that part of it which concerns hygiene, dietetics, and surgery as applied to the treatment of violent lesions, such as fractures, luxations, etc. The Asklepiadi often themselves imparted the principles of medicine to students outside their caste. Lay medicine thus gradually came to supplant sacerdotal medicine, especially after Hippocrates, who through his works, exercised a preponderant influence in the secularization of the science. However, the Asklepiadi, on their side, continued to practise medicine up to the time when the pagan temples fell into complete ruin, through the advance of Christianity. On the columns of the asklepeia and on the votive tables were written the names of those cured by the god, together with indications regarding their various maladies and the treatment by virtue of which the sick had been restored to health. Surgical instruments of proved utility were deposited in the temples. Celius Aurelianus makes mention of a leaden instrument used for the extraction of teeth (_plumbeum odontagogon_), which was exhibited in the temple of Apollo, at Delphi. As a matter of fact, it would seem more natural that this instrument should have been shown in the temple of Æsculapius, he being the god of Medicine, and believed, besides, to be the inventor of dental extraction. One is rather inclined by this to think that the _odontagogon_ may have been deposited in the temple of Apollo before the building of Æsculapian temples. Indeed, who can tell if Æsculapius himself, not yet deified, may not have deposited there a model of the instrument he had invented!