This paper outlines the evolution of ideas on the topic of alcoholic hallucinosis. From 1847 to 1987 numerous descriptive case-histories appeared in the literature. Analysis of these demonstrates that there were some phenomenological features of the illness about which authors were agreed. These were the acute onset of the illness, the predominance of auditory hallucinations and a history of heavy drinking. Protagonists of the delirium tremens school of though drew attention to the slight clouding of consciousness, the presence of the physical symptoms which may accompany an acute confusional state and the possibility of other kinds of hallucinations. Those who favoured the idea that it was a schizophrenic-like illness emphasized the chronicity, the predominance of auditory hallucinations and clear consciousness. Enlightening as these case-histories were, it was impossible to conclude the debate on these unsystematic observations alone.