Certain NUMERALS have had remarkable properties accorded them by philosophical and other speculators. SEVEN has occupied a prominent position. The primitive Chaldeans, in their study of the heavens, became acquainted with seven planets, including the sun and moon, and their week consisted of seven days. With the Egyptians and others the same was the case. Pythagoras saw in this number the three of the triangle and the four of the square,—the two perfect figures. It was considered sacred to Helios and also Apollo. The Hebrew _sheba_ means seven, and was the symbol of a deity[489] before it came to signify an oath. As a charm or amulet, the number was believed to be possessed of great potency. Health was assured by carrying it about the person on a gem or the like. Ebers illustrates this superstition in one of his splendid historical novels; he makes Boges, in giving a ring to Crœsus, speak thus:— “Take this ring. It has never left my finger since I quitted Egypt, and it has a significance far beyond its outward worth. Pythagoras, the noblest of the Greeks, gave it to my mother when he was tarrying in Egypt to learn the wisdom of our priests, and it was her parting gift to me. The number seven is engraved upon the simple stone. This indivisible number represents perfect health, both to soul and body, for health is likewise one and indivisible. The sickness of one member is the sickness of all; one evil thought allowed to take up its abode within our heart destroys the entire harmony of the soul. When you see this seven, therefore, let it recall my heart’s wish that you may ever enjoy undisturbed bodily health and long retain that loving gentleness which has made you the most virtuous and, therefore, the healthiest of men.”[490] As already intimated, the Chaldeans attributed special virtues to certain numbers, of which seven would seem to have been the most highly esteemed. Unfortunately, none of their numerical formulæ have as yet been discovered. The “mamit” or “number” has been referred to before. Lenormant remarks: “More powerful than the incantations were conjurations wrought by the power of numbers. In this way the supreme secret which Hea taught to his son, Silik-mulu-khi, when he consulted him in his distress, was always called ‘the number.’”[491] A remnant of the old belief in the relation of seven to health is the wide-spread superstitious notion that the seventh son of the seventh son is possessed of special healing powers. Curiously enough, I had a visit from such a person, just before writing this; and he as firmly believes that he can cure “the evil” and other ills with certainty as any king that ever exercised the royal gift.