In Libya (Africa) the serpents, as has been already remarked, are very large. For some persons say that, as they sailed along the coast, they saw the bones of many oxen, and that it was evident to them that they had been devoured by the serpents. And, as the ships passed on, the serpents attacked the triremes, and some of them threw themselves upon one of the triremes and overturned it. CHAPTER VI THE BEGINNINGS OF A RATIONAL SYSTEM OF MEDICINE IN GREECE With the lapse of time the religious and mystical features of the treatment carried on at the Asclepieia gave place, more and more, to rational methods, and eventually--it is scarcely possible to mention a date, but probably not many years before the Hippocratic period--these institutions became centres for the spread of medical knowledge of the most practical kind. This is particularly true of the Asclepieion at Cos, where Hippocrates is believed to have received his medical training. It is interesting to note that the mystical features of the temple treatment--features which certainly did not originate with Aesculapius himself or with his sons, Machaon and Podalirius--eventually proved powerless to stay the slow but sure advance of sound medical knowledge. Even during the period when these false elements seemed to be most strongly rooted in the temple methods, there were forces at work which in due time deprived them of much of their pernicious power. This result was inevitable, for an organization which, in order to prosper in its work of doing good to humanity, depended upon the natural superstitiousness of the people, could not possibly thrive for an indefinite length of time. That the evil results did not develop sooner than they did simply shows how powerful and stubborn is the force of superstition. In the absence of trustworthy historical evidence, hypothetical statements only can be brought forward, but there can scarcely be any doubt but that a genuine belief in the power of Aesculapius (deified) to cure disease and restore health persisted for centuries. The custom of recording the case histories on tablets or on the columns of the temple,--for at this period writing was in general use,--and also that of dedicating to the god images which represented (sometimes with a remarkable degree of truthfulness) the pathological condition for which the patient sought relief, contributed very greatly to the substitution of sound learning for religious mysticism and poorly concealed humbuggery.