(4) It is scarcely necessary, after what has been already said, to insist upon the absolute necessity of mental quietude, as far as this can be obtained. This precaution is more or less important in all neuralgic affections; but in migraine and in other trigeminal neuralgias it is almost of more consequence than any other prophylactic measure; and in angina pectoris it is so essential that adoption or neglect of it may easily turn the scale between life and death. All forms of abdominal visceral neuralgia, also, are greatly affected by emotion, and passion or strong excitement of any kind must be scrupulously shunned if the neuralgic habit is to be broken through. Unfortunately, it too often happens that the mental surroundings of the patient cannot be so changed as to enable us to carry out this kind of prophylaxis effectually; and neuralgic cases of this class are among the severest trials of the physician's tact and skill, and too frequently defy his efforts. (_c_) The precautionary measures which are to be adopted, after the neuralgic habit has apparently been fairly broken through, in order to prevent the patient from sliding again into the old vicious groove, can hardly be defined with exactness though their general character will be readily gathered from the picture of the clinical history and pathology of the disease which has been exhibited at large in this work. They mainly consist in the avoidance of severe, and especially of unequal, strains upon bodily or mental powers; and in redoubled carefulness in these respects at those natural crises in the life of the organism which have been shown to exercise so important an influence upon the neuralgic tendency. To a certain extent, also, but with much precaution, we may attempt to modify the peripheral sensibility by what is commonly called a hardening regimen. Thus, with great care, and proceeding in a very gradual manner, we may by degrees accustom the patient to a larger amount of exposure to free air, and even at last to rough weather, so that in the end he may become less sensitive to some of the commonest immediately exciting causes of neuralgia. If one were to construct an advancing scale of such measures, one might arrange them something like this: First, in-door gymnastics, and gentle horse-exercise for out-door work, in fine weather only; then horse-exercise alternated with pedestrianism, sea-bathing in warm weather; and, finally, we should try to reach a stage at which the patient can well endure a ten or fifteen miles' walk or ride every day, and be comparatively careless about the weather. In reaching this latter stage I have seen some patients helped, in an extraordinary degree, by the frequent use of the Turkish bath, followed by douche. Upon this latter subject I beg to offer some remarks, which are the result of pretty careful and extensive study of the effects of the Turkish bath in a variety of chronic nervous diseases.