More than 60,000 patients in the U.S. receive general anesthesia every day. But despite the fact that anaesthesia drugs, like ether, have been around for more than 150 years, it's really only been in the past decade or so that we've gained a better understanding of how they work. Dr. Emery Brown, director of the Harvard-MIT Health Sciences and Technology Program, describes general anaesthesia as a combination of five phenomena: unconsciousness, amnesia, loss of pain sensation, immobility, and