From our modern vantage point, the culinary options of bygone cultures are sometimes difficult to comprehend. It seems that hungry people gobbled down anything they could get their hands on, including dormice (rodents), beaver tails, and fish bladder jam. But while some of the choices seem unusual in hindsight, we can at least grasp their nutritional value. Other foods, however, were just downright dangerous to the human digestive system, and certainly wouldn’t have been on the menu had the...