Although it may appear to be the most obvious application to us, it was not until the second century CE, at the suggestion of the Greek physician Galen, that soap was used as a cleaning agent. Indeed, prior to this period, it appears that soap, which was coarse, skin-irritating, and foul-smelling, was primarily used for medicinal purposes, with Pliny the Elder, a first-century CE chronicler, somewhat grotesquely documenting its use for 'dispers[ing] scrofulous sores' in his Natural History. In short, it's not something we'd want to put in our Scrubba wash bags, let alone apply to our skin. Even after the second century CE, however, the use of soap for cleaning was relatively limited, with European so