East Indies, climate of, a cause of insomnia, 44 Eggs, as an article of food, 66 Electrical test of apparent death, 35 Electricity, atmospheric, 46 use of, 62, 63 Emphysema, insomnia of, relieved with paraldehyde, 80 Energy, diminution of, represented by sleepiness, 2 renewal of, by sleep, 5 Epilepsy, double consciousness in, 205 Ether, hypnotic effect of, 81 inhalation of, 98 use of, in asthma, 101 use of, in convulsions, 110 use of, in irritative cough, 100 Ether, compound spirit of, 81 use of, in delirium tremens, 98 use of, in hepatic diseases, 102 Excrementitious substances, causes of insomnia, 55 Exhaustion, a cause of sleep, 19 relief of with alcoholic stimulants, 76 states of, 64 use of musk in, 68 Exner, experiments of, to test the possibility of dreamless sleep, 14 Eye, state of its secretions during sleep, 8 Facial neuralgia, treatment of, with butylchloral, 83 Fainting, a counterfeit of sleep, 25 Fatigue, a cause of sleep, 19 Fatigue theory of sleep, 20 Fevers, eruptive, treatment of with musk, 68 infective, 57 typhoid, 57 treatment of with cold baths, 73 Flaxseed tea, 100 Florida, climate of, in insomnia, 114 Fonssagrives, observations of, regarding atmospheric electricity and insomnia, 46 Food, lack of, a cause of insomnia, 63 Foot-baths, hot, in the treatment of insomnia, 93, 94 Force, fluctuations of, 15 kinetic, 15 potential, 15 Frank, J. P., case of somnambulism related by, 195 Functional nervous disorders, treatment of with hypnotism, 229 Gairdner, W. T., case of somnambulic lethargy reported by, 174 Gastro-intestinal glands, state of their secretions during sleep, 8 Gelsemium, 90 treatment of fever with, 104 use of, in the wakefulness of children, 112 Generation of ideas, relation of, to molecular movements in the brain, 24 Grasset, case of somnambulism related by, 177 Guérin, observations of, on the _maladie du sommeil_, 30 Guiana, delusions among the Indians of, founded upon dreams, 128 travels in, 42 Guy, observations of, regarding the pulse in sleep, 7 Hallucination, case of, related by Dr. E. H. Clarke, 156 experienced by Sir Edmund Hornby, 150 production of, by drugs, 120 sometimes excited by dreams, 126, 150 Hamilton, Sir William, experiments of, on the possibility of dreamless sleep, 14 Hasheesh, visions excited by, 120 Hayes, Dr. P. S., case of lucid lethargy reported by, 35 Headache, 54 Hearing, persistence of during sleep, 41 sense of, during sleep, 11 Heart, pulsation of, in sleep, 6 Heat, a cause of insomnia, 44 a nervous stimulant, 59 effects of excessive, 47 liberation of, during sleep, 9 Heidenhain, observations of, on hypnotism, 214 Helmholtz, observations of, on liberation of heat during sleep, 9 Hemicrania, treatment of, with butylchloral, 83