Io
2 of the 7 encyclopedias on this shelf carry an entry for Io. Both are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
in Greek mythology, the daughter of the river god, Inachus. Zeus admired the beautiful nymph and used often to visit her. One day when in her company he saw Hera, his jealous wife, approaching. He instantly transformed Io into a heifer. Hera was suspicious, however. She pretended to admire the heifer and finally asked Zeus to give her the beautiful creature. Zeus could not refuse. Hera gave the heifer into the charge of the hundred-eyed Argus. Zeus sent Mercury to Io's relief. Mercury succeeded in slaying Argus, but Hera now sent a gadfly to torment Io. The gadfly drove her over the whole world. She swam the Ionian Sea, which received its name from this circumstance, and finally reached the banks of the river Nile. Hera at last consented to restore Io to the form of a nymph on condition that Zeus pay her no farther attention. See Argus ; Hera
Collier's New Encyclopedia (1921)
in Greek mythology, accord- lemon-yellow crystalline substance, having a saffron-like odor and an unpleasant iodine-like taste. Its odor is most persistent, and can hardly be removed. It is of interest as having a composition similar to that of CHLOROFORM (q. v.), from which it only differs in having iodine in the place of chlorine. It may be prepared by the action of iodine on alcohol in the presence of carbonate of potash. It is employed externally as an application to painful ulcers, and it often gives relief in uterine cancer. In the giv form of iodoform gauze it is used in antiseptic surgery.