“In 1419 Cristoforo de’ Buondelmonti acquired from the island of Andros a mysterious manuscript that was soon to excite the curiosity of philosophers such as Ficino: the manuscript was the Greek translation (by a certain Philippos) of the Horapòllonos Neiloùs ieroglyphikà.
The original author, Horapollo–or Horus Apollos, or Horapollus–was thus qualified as “Nilotic.” Although it was taken as genuinely archaic throughout the Renaissance, scholars now believe this text to be a late Hellenistic compilation, dating from as late as the fifth century AD.
As we shall see, although certain passages indicate that the author did possess exact information about Egyptian hieroglyphs, the text was written at a time when hieroglyphic writing had certainly fallen out of use. At best, the Hieroglyphica seems to be based on some texts written a few centuries before.
The original manuscript contained no images. Illustrations appeared only in later editions: for instance, though the first translation into Italian in 1547 is still without illustrations, the 1514 translation into Latin was illustrated by Dürer.
The text is divided into short chapters in which it is explained, for example, that the Egyptians represented age by depicting the sun and the moon, or the month by a palm branch.
There follows in each case a brief description of the symbolic meaning of each figure, and in many cases its polysemic value: for example, the vulture is said to signify mother, sight, the end of a thing, knowledge of the future, year, sky, mercy, Minerva, Juno, or two drachmas.
Sometimes the hieroglyphic sign is a number: pleasure, for example, is denoted by the number 16, because sexual activity begins at the age of sixteen. Since it takes two to have intercourse, however, this is denoted by two 16’s.
Humanist philosophical culture was immediately fascinated by this text: hieroglyphs were regarded as the work of the great Hermes Trismegistus himself, and therefore as a source of inexhaustible wisdom.
To understand the impact of Horopollo’s text on Europe, it is first necessary to understand what, in reality, these mysterious symbols were. Horopollo was describing a writing system, whose last example (as far as Egyptologists can trace) is on the Theodosius temple (AD 394).
Even if these inscriptions were still similar to those elaborated three thousand years before, the Egyptian language of the fifth century had changed radically. Thus, when Horopollo wrote his text, the key to understanding hieroglyphs had long been lost.”
Umberto Eco, The Search for the Perfect Language, translated by James Fentress, Blackwell. Oxford, 1995, pp. 145-6.