Abnormal service

Perhaps something more subtle than Kevin McCarron realises was going on at the Cairo dinner he describes ("Courtesy calls", 20 November). His host was no doubt aware that etiquette dictates that the host begins by pouring port for the guest to his right before starting the decanter on its leftwards passage. The host must have balanced the risk of quietly adding to the Egyptian professor's excessive intake against that of the said guest's lurching across the table in desperate pursuit of the retreating alcohol.

A. H. Harker, Department of physics and astronomy, University College London.