The History of Medicine in Its Salient Features

who stood next to the sage of Cos in age and distinction, was a dissector of animals, and in a work on zootomy described the heart, the large blood-vessels, and a greater number of the smaller vessels than had been recognized in earlier works. He agreed with his contemporary Plato, as well as one of the less authentic Hippocratic writings ("On the Heart")i in looking upon the heart as the source that sent its streams to all parts of the body. Diocles knew the oesophagus, the biliary ducts, the caecum, the ureters, and the Fallopian tubes. He was the inventor of a bandage for the head, and of the graph- iscus, a spoon-like instrument later used in the Roman armies to extract arrows and spears from wounds. He made use of opium as an anodyne, and distinguished pleurisy from pneumonia. Praxag- oras of Cos was the first to differentiate veins andarteries, the former filled with blood, the latter with vital air, or pneuma. He recorded the local conditions of pleurisy, was the first among the Greeks to recognize the importance of the pulse in diagnosis, and advised laparotomy, as a last resort, in intestinal obstruction, though there is no evidence that this operation was actually put in practice in his age. Diocles and Praxagoras are classed among the Dogmatists, who were under the influence of medical speculations concerning the pneuma (which in the opinion of Diocles was renewed by respiration) and concerning the four humors. For example, both Diocles and Praxagoras att...