[66] According to Dr. Edgar Bérillon, who was the first systematically to apply the hypnotic method to the education of children (see his paper, "De la Suggestion envisagée au point de vue pédagogique" in the Revue de l'Hypnotisme, vol. i. (1887), p. 84), the percentage of those who can be hypnotised is more than 80, and he asserts that suggestibility varies directly as the intellectual development of the subject. He classes under four heads the affections which can be successfully treated by hypnotic suggestion. (See the Revue de l'Hypnotisme, July 1895.)
(1) Psychical derangements caused by acute diseases; in particular, insomnia, restlessness, nocturnal delirium, incontrollable vomiting, incontinence of urine and of fæces.
(2) Functional affections connected with nervous disease: chorea, tics, convulsions, anæsthesiæ, contractures and hysterical paresis, hysterical hiccough, blepharospasm.
(3) Psychical derangements, such as habit of biting nails, precocious impulsive tendencies, nocturnal terrors, speaking in sleep, kleptomania, nervousness, shyness.
(4) Chorea, hysteria, epilepsy, or mental derangements considered as resulting from the combination of several nervous diseases.
Scattered about in the Revue de l'Hypnotisme the reader will find numerous illustrative cases. Specially characteristic are those recorded in the number for July 1893, p. 11, and April 1895, p. 306.
For reports of hypnotic cure of onychophagy, see Bérillon, the articles already quoted; Bourdon, Revue de l'Hypnotisme, November 1895, p. 134; Bouffé, Revue de l'Hypnotisme, September 1898, p. 76.
For reports of hypnotic cure of even graver habits, see Van Renterghem and Van Eeden, Psycho-Thérapie, p. 250; Bernheim, Revue de l'Hypnotisme, December 1891, a case in which the habit had become quite automatic and irresistible, and where every other method of treatment had failed; also De la Suggestion; Schrenck-Notzing, Die Suggestions-Therapie bei krankhaften Erscheinungen des Geschlechtssinnes; Bérillon, Revue de l'Hypnotisme, July 1893, pp. 12, 14, 15; Bourdon, Revue de l'Hypnotisme, November 1895, pp. 136, 139, 140; Auguste Voisin, Revue de l'Hypnotisme, November 1887, p. 151.
For cures of enuresis nocturna, see Liébeault, Revue de l'Hypnotisme, September 1886, p. 71; Bérillon, Revue de l'Hypnotisme, June 1894, p. 359; Van Renterghem and Van Eeden, Psycho-thérapie; Paul Farez, Revue de l'Hypnotisme, August 1899, p. 53. This author recommends the method of suggestion in normal sleep.
Liébeault, in the Revue de l'Hypnotisme for January 1889, gives twenty-two cases in which hypnotic suggestion was used in the moral education of children from the age of fourteen months upwards, with the aim of curing, e.g. the habit of lying, excessive developments of emotions, such as fear and anger, and precocious or depraved appetites; and of improving the normal faculties of attention and memory. He reports ten cures, eight improvements, and four failures.