My aged and ageing brain finally dredged up another memory of herbal vinegars. Herbal Vinegar by Maggie Oster is the name of the book, still sold by different suppliers and probably also in your local library system. In a previous post to this query, I mentioned that more modern recipes for 4 Thieves Vinegar do not contain Rue. Rue is not a good idea for human consumption. The original vinegar was used to wash down the thieves to disinfect them as they broke into homes of victims of the Plague. Later versions were prized for salad dressings.