nervous organs — Disorders of circulation and nutrition — Hyperæmia of the brain — Anæmia and starvation of the brain — Effects of tea and coffee — Effect of alcohol — Inflammations, degenerations, and tumors affecting the brain — Excitement of the brain by diseased conditions of the blood. 38

CHAPTER III.

REMEDIES FOR INSOMNIA.

Serious consequences of insomnia — Its relation to cerebral diseases — Treatment of insomnia by moderation and control of the cerebral circulation — Remedial agents — Nervous stimulants and nervous sedatives — Heat — Baths — Massage — Electricity — Counter-irritants — Food — Digitalis — Camphor — Musk — Valerian — Cannabis indica — Belladonna — Hyoscyamus — Stramonium — Phosphorus — Acids — Opium — Cold — Alcohol — Paraldehyde — Ether — Chloroform — Chloral — Butylchloral hydrate — Amyl nitrite — Opium and opiates — Bromides — Hops — Gelsemium — Conium. 56

CHAPTER IV.

TREATMENT OF INSOMNIA IN PARTICULAR DISEASES.

Insomnia in acute affections of the brain — In insanity — In chronic alcoholism and delirium tremens — In diseases of the heart and blood-vessels — In angina pectoris — In diseases of the respiratory organs — In asthma — In renal diseases — In diseases of the liver — In gastro-intestinal diseases — In febrile conditions — In rheumatism and gout — In lithæmia — In syphilis — In disorders of nutrition — During pregnancy and after parturition — In spasmodic diseases — In childhood — In old age.  92

CHAPTER V.

DREAMS.

Physiology of perception and of dreaming — Definition of the act of dreaming — Revery — Production of illusions and hallucinations by drugs and by disease — Effects of hasheesh — Effects of acute disease — Association of ideas — Memory of past sensations — Dreams produced by excitement of the different organs of sense — Persistence of dream-impressions after waking — Experience of M. Baillarger — Of Professor Jessen — Belief of savages in the reality of dreams — Sensory dreams — Intellectual dreams — Repetition of dreams — Incoherence of dreams — Cause of the superior vividness of certain dreams — Duration of dreams — Dreams excited by morbid states of the body — Prophetic dreams — Their causes — Clairvoyant dreams — Hallucinatory dreams — Sir Edmund Hornby’s experience — Hallucinations — Case related by Dr. E. H. Clarke — Revelation through dreams — Revival of memory in dreams.  116

CHAPTER VI.

SOMNAMBULISM.

Causes of somnambulism — Physiology of somnambulism — Varieties of the disorder — Maury’s classification — Classification of Ball and Chambard — Diagrammatic representation of their classification — Somnambulic lethargy — Illustrative cases — Somnambulic dreams — Night terrors — Somnolentia or sleep-drunkenness — Sleep-walking — Illustrative cases — Condition of the special senses in somnambulism — Relation of memory to the somnambulic paroxysm — Illustrative cases — Occasional recollection of incidents connected with the somnambulic dream — Resemblances between the somnambulic state and the condition of post-epileptic mania — Somnambulic visions — J. P. Frank’s case — Mesnet’s case — Somnambulic life — Its likeness with the double-consciousness of certain forms of epilepsy — Illustrative cases — General theory of somnambulism. 166

CHAPTER VII.

ARTIFICIAL SOMNAMBULISM OR HYPNOTISM.

Antiquity of the phenomena of hypnotism — Modern observations — Physical conditions favorable to the phenomena — Methods of inducing the hypnotic state — Duration of hypnotic sleep — Rudimentary states of hypnotism — Investigations of the Society for Psychical Research — Mind-reading — Physiological explanation of the process — Charcot’s observations on artificial somnambulism — Cataleptic variety of the hypnotic state — Lethargic variety — Somnambulic variety — Hypnotic clairvoyance — Exalted sensibility of the brain in hypnotic states — Susceptibility to suggestions from without — Phenomena of so-called spiritualism — Table-rapping — Planchette — Therapeutical employment of hypnotism — Metaphysical healing.  212

CHAPTER I.

THE NATURE AND CAUSE OF SLEEP.

Natural sleep is that condition of physiological repose in which the molecular movements of the brain are no longer fully and clearly projected upon the field of consciousness. This condition is universally observed in all healthy animals; and its recurrence is intimately associated with the diurnal revolution of the earth, and the succession of day and night. The disappearance of daylight is, for the majority of living creatures, the signal for cessation of active life. Though its onset may be for a time delayed by an effort of the will, the need of rest at length overcomes all opposition, and the most untoward circumstances cannot then prevent the access of unconsciousness. The story of the sailor-boy, sleeping on “the high and giddy mast,” is familiar to every one. An officer in the United States Navy has assured me of more than one instance in which men had fallen asleep under his own eyes, oppressed by exhaustion, during the roar of a long continued bombardment. Thus produced, the relation of cause and effect between weariness and sleep becomes very