Medieval anesthesia--the spongia somnifera.

The author reviews in detail the literature concerning medieval general anesthesia in general and the so-called spongia somnifera in particular. In spite of claims to the contrary, he concludes that there is no evidence that medieval physicians had at their disposal general anesthesia for their patients undergoing surgery. On the contrary, there is evidence that the spongia somnifera was ineffective and that what kept the tradition of its effectiveness in the literature may have been the everlasting hope for surgical analgesia.