what i posted is just one book's embellishment (—which now, upon re-reading, seems much stranger than it initially appeared, for some reason.. my apologies). or do you mean the egg in general? google is your friend.
a preservative against poison, and a cure for the plague; a panacea. the shell of a new egg being pricked, the white is blown out, and the place filed with saffron or a yolk of an egg mixed with saffron. (infoplease.com)