Thomas Nichols’s lapidary, or book on gemstones, explains how specific stones can affect dreams. For example, he shares reports that wearing a ruby in an amulet or drinking ground-up rubies will drive away “terrible dreams” as well as sadness, evil thoughts, and evil spirits. It was a widely held belief that gemstones could help control dreams. Wearing a crystal or ruby around one’s neck prevented nightmares. Children were advised to wear emeralds to avoid nightmares. Wearing an amethyst caused exciting dreams and prevented drunkenness. And wearing an onyx to bed caused the wearer to dream of a departed friend.
Plants, as we've seen throughout the exhibition, were used for many medicinal purposes, and controllin dreams was yet another way to use them. Nicholas Culpeper composed a directory of over three hundred plants, and it includes several that could control dreams. One entry describes polypody, a variety of fern thought to be most medicinally powerful when it grows on oak stumps or trunks. Drinking liquid distilled from its roots and leaves prevents “fearful or troublesome sleeps or dreams.”
A very popular book with cures and recipes for a wide range of ailments, from how to heal ringworm to how to “make the haire fall off” was The secrets of Alexis. One recipe explains how to see wild beasts in a dream; it also includes a number of recipes for inducing sleep.
Various animal parts were used in recipes in much the same way as plants or gemstones. Edward Topsell's Historie of serpents is a spectacularly illustrated and hand-colored book, devoted to serpents (including dragons). According to Topsell, eating the wine-soaked tongue or gall of a dragon could prevent nightmares.