The blood-vessels were supposed to contain both blood and air, and were called φλέβες; the trachea was called an “artery.” The brain was considered as merely a gland which condenses the ascending vapours into mucus. The office of the nerves was to convey the animal spirits throughout the body. We must not forget that the science of anatomy was extremely imperfect even at the beginning of the present century. “When,” says Littré,[388] “one searches into the history of medicine and the commencement of the science, the first body of doctrine that one meets with is the collection of writings known under the name of the works of Hippocrates. The science mounts up directly to that origin, and there stops. Not that it had not been cultivated earlier, and had not given rise to even numerous productions; but everything that had been made before the physician of Cos has perished. We have only remaining of them scattered and unconnected fragments. The works of Hippocrates have alone escaped destruction; and by a singular circumstance there exists a great gap after them as well as before them. The medical works from Hippocrates to the establishment of the school of Alexandria, and those of that school itself, are completely lost, except some quotations and passages preserved in the later writers; so that the writings of Hippocrates remain alone amongst the ruins of ancient medical literature.” It is vain to inquire how Hippocrates acquired a knowledge which seems to us so far in advance of his age. Was Greek wisdom derived from the East, or was its philosophy the offspring of the soil of Hellas? Such questions have often been discussed, but to little purpose. There would seem to be every reason to suppose that Greek medicine was indigenous. We have no means of knowing how long philosophy and medicine had been united before the time of Hippocrates. The honour of affecting the alliance has been ascribed to Pythagoras. Several of the Greek philosophers speculated about medicine. We have seen that besides Pythagoras, Empedocles and Democritus did so, although it is not probable that they followed it as a profession. The Asclepiadæ probably brought medicine to a high state of perfection, but the work these priest-physicians did is a sealed book to us. All was darkness till Hippocrates appeared.