This condition, in which severe confusion, disorientation, and restlessness are the principal features, appears to have been first clearly described by Bell (1845), who noted that about 2½ per cent. of the patients admitted to his asylum showed a particular syndrome: they were normal people who were admitted after about a week's acute illness; their appearance and speech suggested fever and delirium like a typhoid state; understanding was limited; they were apprehensive, with distressing but confused delusions; they disliked and suspected their food, and were not sensible enough to be thirsty; they tried to get out of bed, were sometimes violent, and struggled strongly when held. The course of the illness was rapidly downhill, but about a quarter of the patients suddenly made a complete and permanent recovery at the end of two to three weeks, the remainder dying in the same time. There were no specific post-mortem findings.