Researches along this line in Germany and England have shown that the fatigue produced by studies varies, and that it is possible by arranging sequence of studies to remove fatigue produced by one study through the rest furnished by another. It has been found that biology exhausts least and mathematics and grammar most. While there is undoubtedly a spirit of emulation stirred by these last two studies which is injurious, the limited associations affected by them are further a source of fatigue as well. The numerous associations of biology afford points of rest on the one hand while not tending to emulation on the other. It is this spirit of emulation, with its attendant alternation of worry and hope, that causes so many of the acquired nervous disorders of the adult, and which hence is obviously much more potent for evil in the child. Physical and mental training in the special asylums for imbeciles and idiots gives such splendid results that it is surprising that parents, and especially those charged with bad heredity, are not encouraged and advised by their physicians and friends to try from the first year of the child's life special measures for their preservation. If a persevering physical and psychic management of the weak-minded gives such admirable results in asylums, it would be still better if the child could be trained from the earliest period of its life. This subject is ignored by the public, and in every case not sufficiently appreciated. First of all try to preserve patients of a nervous or of a weak constitution. They should know in what state of health they are living, they must be informed of the great danger of matrimonial union with a person of the same tendencies, and especially when consanguinity exists between them. The greatest care is to be given to children of this class. Experience has already led to the conclusion that mental and physical overwork increases this defect: hence young brains must not be over-excited with worry or emotionalism. The will of children ought to be cultivated and strengthened. Their minds should be methodically educated. The bodily functions should never be artificially stimulated in any way, to increase unduly the assimilation of the food. Development of the intelligence, the sensibility and the physical training, should be looked after in the same way. Once a plan of living is laid down it should be followed. Success depends on this. The great influence of hygienic conditions (air, light, food, dress, habitation, sleep, muscular exercise, &c.) should not be forgotten, for without them efforts made for mental training are useless. By putting these methods into execution an increase of the congenital taint is prevented, and such methods perceptibly amend the psychopathic depreciation which in the usual way of living would certainly become worse. The object very often thus secured is double; aggravation has been prevented, amelioration has been obtained.