Composed by a Polish Jew identified only as Elḥanan—probably in the 1730s—Virtues and Medicines: A Large Volume of Virtues, Medicines, Amulets, and Fortunes consists of 290 handwritten folio pages dealing with what scholars call the “practical kabbalah”: mystical knowledge, in this case in the form of recipes, that could be used to cure diseases, bring material or marital success, ward away demons, and so forth. Agata Paluch describes its contents:
Elḥanan’s manuscript contains a well-known recipe for the production of gold ink. It recommends emptying an eggshell and filling it with mercury. After the shell is sealed with wax or tar, it is supposed to be put under a hen among the eggs that are waiting to hatch. In this case, the result of the mercury egg’s hatching would be an ink that has all the features of gold. . . .
The idea of augmenting the qualities of certain materials was a straightforward consequence of understanding matter as imbued with creative and active forces. Kabbalistic practitioners often attempted to tap into and manipulate these forces with the abilities of their minds. A prayer recitation and mental focus (kavannah or “intention”) on a divine name would seemingly add to the potency of matter or help to change its qualities. . . .
Elḥanan’s compilation offers a number of recipes to treat koltun, [a] disease that causes hair-matting, also known plica polonica. One of the recipes to cure this unfortunate condition recommends, among other things, an adjuration that employs a series of divine names intended to get rid of the demonic element responsible for causing the ailment in human hair. After adjuring an angel whose power extends over [this particular demon], one is to strike it with “the name of eyes”—that is, with the Tetragrammaton written with circles and lines that resemble the shape of eyes—and thus focus his intention on both the ocular shape of the Tetragrammaton and the numerical value of 1,600 for the number of “forces” accompanying the culpable spirit.
Read more on History of Knowledge: https://historyofknowledge.net/2019/04/11/practical-kabbalah-and-practical-knowledge-kabbalistic-manuals-and-natural-knowledge-in-early-modern-east-central-europe/