MERCURIE, MERCURIUS, MERCURYE. Mercury, son of Jupiter and Maia (one of the Pleiades), was born on Mount Cylennius, hence his byname of location, Cylennius. At an early stage of development, his myth took over the aspects of the myth of Hermes, the Greek messenger of the gods. He was Jupiter's winged messenger, the god of cunning, wit, and eloquence, and became the guide of souls, a function of Hermes Psychopompos (Met I and II). Isidore says that Mercury devised deception (Etym VIII.ix.33) and that the magic wand with two snakes entwined, or caduceus, represents the power of language (Etym VIII.xi.48). Petrus Berchorius adds that the wand signifies eloquence (De formis figurisque deorum, fol. 6^ra, 46-55, fol. 6^rb, 9-16). Mercury was famous for his feat of putting the hundred-eyed Argus to sleep. Jupiter loved Io, whom he changed into a white heifer to save her from Juno's anger. Juno set Argus with his hundred eyes to guard Io and to report to her any visits from Jupiter. Jupiter, however, commanded Mercury to slay Argus, quite a project since the hundred eyes were never closed all at the same time. Taking his sleep-producing wand and his reed pipe, Mercury approached Argus. He put him to sleep with the aid of the music and the wand, then slew him (Met I.668-721).

The winged Mercurie appears to Arcite and bids him be merry, KnT 1384-1386; he carries his "slepy yerd," KnT 1387, which, Berchorius says, induces sleep. He is arrayed as when he put Argus to sleep, KnT 1388. The poet Marcian (Martianus), who has written about the wedding of Mercurie and Philology, must hold his peace, for both his pen and his tongue are too meager to describe the marriage of Januarie and May, MerchT 1732-1735. To excuse Eneas, the book says that Mercurie commands him to leave Dido and go to Italy, HF I.427-432, LGW 1295-1300. Mercurie helps Ulixes escape Circe's enchantments, Bo IV, Metr 3.16-23. Boethius does not mention Mercury by name but writes: Sed licet variis malis / Numen Arcadia alitis, which Chaucer expands to: "But al be it so that the godhede of Mercurie, that is cleped the bridd of Arcadye, hath had merci on duc Ulixes." Troilus invokes Mercurie who loved Hierse, Tr III.729. Mercurye acts as psychopompos or soul-guide to Troilus, Tr V.321, 1826-1827. Mercury provides an abode of refuge for the fleeing Venus, Mars 113-121.

Mercurie, Mercury is the second planet, counting away from the earth (see Ptolemaic map). It is exalted (or has its greatest power) in Virgo, and Pisces is the sign in which it is weakest or has its depression (Tetrabiblos I.19). It is thus the very opposite of Venus, whose exaltation is Pisces and whose depression is Virgo. Mercury controls speech and thought (Tetrabiblos III.12). Those born under Mercury are studious and love ease and rest (Confessio Amantis VII.755-770). Mercury is quicksilver in alchemy.

The children of Mercury are "contrarius" to the children of Venus, WBP 697-698. Mercury's children love wisdom and science, WBP 699. The illustration in Christine de Pizan's Epître d'Othée, British Library Ms. Harley 4431, fol. 102^r, shows a group of monks discoursing, while Mercury presides in the stars above them (Seznec, plate 23). Pisces is Mercury's depression but Venus's exaltation, WBP 703-704. The sun is in Mercury when Apollo whirls his chariot up to the mansion of Mercurius, SqT 671-672. The sixth inequal hour of Saturday belongs to Mercury, Astr II.12.25-26. [Aglawros: Argus¹: Cilenios: Gemini: Hierse: Marcian: Mars: Venus]

Mercurie is quicksilver in alchemy, CYT 772, 774, 827, 1431, and is also called the Dragon, CYT 1438.

Mercurie, the ME variant, appears twice initially, WBP 699; Tr III.729; six times in medial positions, WBP 697, 703, 705; CYT 1438; HF I.429; LGW 1297; and twice in final rhyming position, KnT 1385, MerchT 1734. Mercurius, the Latin form, appears once medially, SqT 672, and in the Treatise on the Astrolabe; Mercurye, a spelling variant, appears twice medially, Tr V.321, 1827.