When it comes to “how-to” books, alchemy poses particular problems. Medieval alchemical treatises claimed to offer detailed advice on a host of spectacular products and processes, ranging from the Philosophers’ Stone, a transmuting agent capable of turning base metals into gold and silver, to medicinal elixirs that offered cures for otherwise intractable diseases, as well as the prospect of renewed youth and an extended life span. Yet, at least to modern eyes, no amount of “know-how” could teach anyone how to make these things—they are impossible practices, which no alchemist can ever have successfully carried out, nor described in accurate, replicable instructions. What, then, is the function of a “manual” of alchemy?
Ancient recipes are usually short texts; one can easily find more than one recipe written on a single papyrus sheet or on the page of a Byzantine manuscript. Despite their brevity, however, they open an invaluable window onto a wide array of techniques and practices used to manipulate the natural world. Ancient recipes could pertain to various fields of science and technology—from cosmetics to cookery, from agriculture to horse care. In this post, particular attention will be devoted to two contiguous and, to a certain extent, overlapping areas of expertise: medicine and alchemy. As we will see, the works of two important authors, Oribasius and Zosimus of Panopolis, reveal the ways that recipe collections forged new forms of knowledge transfer in the fourth century CE.