After 150 years of clinical anaesthesia, the molecular events that lead to anaesthesia have not been determined. This is not because of a lack of ideas [16-19, 56, 571. However, most striking to the observer is the paucity of long-term and systematic studies. The present review describes results from such a study. The long-term goals were: first, to understand how anaesthetics affect membrane protein function and second, to determine if clinical and molecular actions of anaesthetics rnay be correlated.