An ominous character was attributed to the red coral, especially the more highly colored varieties. If worn so that the substance came in direct contact with the skin, it was asserted that the color would pale, the coral also losing its brightness if the wearer became ill, or even if he were only threatened with severe illness. The same effect was said to be induced if some deadly poison had been taken. Cardano writes that he more than once observed this phenomenon, and he thinks that in these cases, where the wearer was not yet attacked by disease, its threatening “vapor,” though not strong enough to provoke decided symptoms in the human body, was sufficiently powerful to offset the more delicate and subtle essence of the mineral substance. Of course, for us the mineral would be much less sensitive than flesh and blood, but the sixteenth century writers, and to a still greater degree those of an earlier time, attributed to stones not only life in a general way, but old age, disease, and death, in a very positive sense.[235] Rabbinical tradition tells of a wonderful luminous stone placed by Noah in the Ark. This stone shone more brilliantly by day than by night, and served to distinguish the day from the night when, during the flood, neither sun nor moon could be seen.[236] According to another Jewish legend, Abraham is said to have built a city for the six sons Hagar bore to him. The wall with which this city was surrounded was so lofty that the light of the sun was cut off, and to offset this Abraham gave to his sons enormous precious stones and pearls. These exceeded the sun in brightness, and will be used in the time of the Messiah.[237] Ælian relates the following tale of a luminous stone. A woman of Tarentum, named Heracleis, who was a pattern of the domestic virtues, lost her husband and mourned sincerely for him. Her grief made her compassionate, for when a young stork just learning to fly lost its strength and fell to the ground before her, Heracleis picked up the helpless bird and tended it carefully until its strength returned and it was able to fly away. A year later, when the woman was outside the house enjoying the bright warm sunshine, she saw a stork flying toward her. As the bird passed over her head, it let fall a precious stone into her lap. Heracleis took the stone with her into the house, feeling by an infallible instinct that the stork which had dropped it was the one she had cared for in the previous year. During the night she woke up, and was astonished to see that the room was lighted up as though by many torches, the radiance proceeding from the stone bestowed by the stork as a proof of its gratitude.[238]