In the case also of healthy people who can afford to be massaged daily, vital functions can be rendered more active and youthfulness prolonged; and for those who do not possess facilities for being massaged by others, they can perform it themselves by friction, rubbing the body at rising and just before going to bed. The Swedish movements can also be performed not only by free gymnastics, but also by the use of mechanical apparatus, such as that invented by Dr. Zander of Stockholm. These movements, combined with massage, also give good results in many of the above-mentioned ailments, but it would lead us too far to enlarge upon them here. Much more strenuous for the body than Swedish movements and massage are the exercises of sports, a complete description of which would exceed the limits of the present work; but whether it be football, tennis, golf, athletics, or cycling, the great object in all is to easily create perspiration, by which the benefits described in the chapter on hygiene of the skin and kidneys are obtained. It goes without saying, that a diseased state of the kidneys excludes all kinds of violent exercise which require a severe bodily movement. By means of sport the processes of oxidation are also rendered more active, and thus obesity can be prevented and cured, and at the same time the waste products are more thoroughly consumed. Neurasthenic conditions, insomnia, etc., may be improved if the sport adopted does not lead to too great fatigue; otherwise they may be made worse. Taking into consideration, however, the conditions of the circulatory mechanism, sport is a two-edged sword. If undertaken in moderation all sport can improve our physical condition; but it may prove disastrous if reason be not exercised and it is indulged in to excess. By the strong muscular exertions referred to an irritation of the splanchnic nerves takes place, resulting in a high blood-pressure; more blood will pass with greater vigor through the arteries and capillaries, which, consequently, become dilated. If this occurs too frequently they will, as is only natural, lose their elasticity, in which case degeneration of the arteries and development of arteriosclerosis may follow. When a succession of severe muscular exertions takes place an accumulation of blood occurs in the right side of the heart, and, as the right ventricle cannot empty itself, shortness of breath, and even death, may result. The left ventricle then becomes dilated, and such dilatation of the heart not infrequently persists for a long time, even in persons who have been in good health before undertaking severe exercises. If, therefore, the normally healthy may suffer from an irrational indulgence in sport, how much more fatal must be the results to those with heart or kidney complaints, and with degenerative conditions of the blood-vessels?