Thus the very origin of the term rendered it comprehensive in meaning. Even the greater deities of ancient Greece were, in a sense, local--the occupants of prescribed domains; Poseidon might logically be called the _genius_ of the sea, Demeter of the corn-land; while lesser deities were always associated with particular spots and often unknown elsewhere. But mediaeval usage of the word στοιχεῖον and of its derivatives tended to widen the meaning of the word yet more. A verb στοιχειοῦν[667] was formed which properly meant to settle a _genius_ in a particular place--either a beneficent _genius_ to act as tutelary deity, or an evil _genius_ whose range of activity would thus be circumscribed within known and narrower limits; but it was used also in a larger sense to denote the exercise of any magical powers. A corresponding adjective στοιχειωματικός[668] was applied to anyone who had dealings with genii or familiar spirits, and more vaguely to wizards in general. Thus the famous magician Apollonius of Tyana is described as a ‘Pythagorean philosopher with power over _genii_’ (φιλόσοφος Πυθαγόρειος στοιχειωματικός)[669]; and two out of his many miracles may be taken as typical of his exercise of the power. Once, it is recorded, he was summoned to Byzantium by the inhabitants and there ‘he charmed (ἐστοιχείωσεν) snakes and scorpions not to strike, mosquitoes totally to disappear, horses to be quiet and not to be vicious either towards each other or towards man; the river Lycus also he charmed (ἐστοιχείωσεν) not to flood and do damage to Byzantium[670].’ In the first part of this passage the verb is undoubtedly used in a very lax sense, for snakes, scorpions, mosquitoes, and horses can hardly have been conceived to have their own several _genii_ or guardian-spirits upon whom magic could be exercised; but the charming of the river Lycus certainly suggests the restraining of the στοιχεῖον or _genius_ of the river within settled bounds. This stricter sense of the word however comes out more clearly in relation to good _genii_ who were settled by magical charms in any given object or place. Hence even the word στοιχεῖον reverted to a material sense, and was sometimes employed to mean a ‘talisman[671]’--an object, that is, in which resided a _genius_ capable of averting wars, pestilences, and suchlike. _Genii_ of this kind, we are told, were settled by the same Apollonius in the statues throughout Constantinople[672], where the belief in their efficacy seems to have been generally accepted; for there was to be seen there a cross in the middle of which was ‘the fortune of the city, namely a small chain having its ends locked together and possessed of power to keep the city abounding in all manner of goods and to give her victory ever over the nations (or heathen), that they should have strength no more to approach and draw nigh thereto, but should hold further aloof from her and retreat as though they had been vanquished.