Who was known as "The Sibyl of the Rhine"?

What an inspirational and very interesting woman. Thank you for the great question and fantastic background information.

I only knew of her music composition. I think Patricia Routledge starred in a British sitcom, "Keeping Up Appearances" that aired in the US several years ago on PBS - very good actress.

She was the first proponent of suspending an amethyst chunk over a pan of boiling water, allowing the condensation to drop off and collecting it. It was then recommended for using on sores and cuts. It was even consumed for benefit.