Hobson's heavy drinking and alcohol intoxication, threatened by signs of emergence of the temperance movement, play a prominent role in the plot until he awakens one morning (1:28) to a buzzing sound. When he opens his eyes he hallucinates swarms of mosquito-like insects, then a giant rat. Since there is no other sign of delirium Substance-Induced Psychotic Disorder fits. During a house call (1:31) his physician elicits tremors which do not seem quite consistent with asterixis (liver flap) and diagnoses chronic alcoholism.
Charles Laughton, John Mills, Brenda De Banzie