(1) Patients must walk every day, preferably at two distinct times, separated by not too short a rest, on the prescribed terrain as far as they can without over-fatigue. No one better than the patient can definitely limit the day's work to just below the fatigue point. It would be absurd to prescribe the length of each walk, which varies from day to day owing to numerous causes, all of which are out of our control. The power of walking increases, and the increase is in many cases so perceptible from one week to another during the treatment that the patient at the end of his cure is often able to undertake without any danger long walks, which at the beginning of his cure would have been impossible.

(2) All patients who are undergoing the terrain-cure, but especially all heart patients, must avoid all temporary overstrain of the heart. This is best attained, in certain cases of heart disease, by the prohibition of too steep paths, and by forbidding the patient to walk so quickly as to produce dyspnoea.

(3) As a third rule in the terrain-cure I make it a custom to prescribe that the walk be taken early in the day and that all tiring movements be avoided at the close of day; this especially, because for several hours after mountain-climbing its effect on sleep is disastrous.

The "saccadic type of respiration," which is partly used with Oertel's "heart massage" (see above), and partly in connection with terrain-cure, consists of expiration in two stages in time with the patient's footsteps, first ordinary expiration and directly after that a forced use of the muscles of expiration, which drives out a certain extra quantity of pulmonary air. Oertel has illustrated by figures that the ventilation of the lungs becomes greater, and he maintains that the cardiac impulse becomes slower, more regular, and stronger. This result, however, can be achieved without the "saccadee" respiration, which, besides being entirely useless, mountain-climbing by itself producing sufficiently deep respiratory movements, has the great disadvantage of introducing discomfort into the patient's walk.

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Medical experience, especially in affections of the heart, varies considerably. In hospital practice a doctor often sees advanced cases of arterio-sclerosis, of severe endocarditis and pericarditis, and of lingering infectious diseases where one or other of these affections has caused myocardiac changes, which necessitate the greatest care in physical exercise and, above all, cause doubt as to terrain-cures (p. 144). A great percentage of these heart cases are hampered by severe cardiac incompetence, so that all active and severe exercises are contra-indicated. These cases are also often complicated by severe inflammatory processes in the kidneys, which also contra-indicate hard physical exercise.

In a sanatorium the percentage of heart cases suitable for terrain-cures in which the heart is still strong enough to be treated by active exercises, and in which the kidneys are still normal or nearly normal in function, is much greater. Thither flock a number of individuals who, having weakened their hearts by alcohol or tobacco, have not arrived at that stage of advanced fatty degeneration which forbids both terrain-cure and all hope of a long and tolerably-comfortable existence. The patients suffering from obesity who undergo treatment, especially at alkaline-saline sanatoria, need the cure both for their obesity and also for the condition of the heart. Of those patients suffering from anaemia, as well as those who are recovering from severe infectious diseases, many are sent to the cure because of their imperceptible heart-beat, weak "distant" heart sounds, and small, weak, often uneven pulse, which symptoms are sometimes accompanied by an increased heart dulness, so that each patient according to his strength can exercise his heart, the walls of which are absolutely or relatively (to the dilatation) thin. Patients suffering from gout and mild cases of diabetes often receive great benefit from the terrain-cure, not only on account of gout or diabetes, and of the obesity by which these diseases are often accompanied, but also on account of the improved condition of the heart. And, lastly, institutions for the terrain-cure are often frequented by patients who have just such cardiac changes resulting from valvular disease as can be benefited by this excellent system of gymnastics.

Opinions concerning the terrain-cure and its use in valvular diseases are very variable, and I must here take the opportunity of referring to them somewhat in detail.

I think, however, that we all agree that the terrain-cure is most valuable and least dangerous in cases in which compensatory hypertrophy is not yet fully developed or in which, generally after many years' duration, it is incomplete owing to commencing fatty degeneration or other changes, but which have not reached a high degree of cardiac incompetence.

In most cases we have to do with the left auriculo-ventricular and aortic orifices. In mitral incompetence the heart walls hypertrophy on either side of the valves, and we thus find thickening of the walls both of the left ventricle and auricle. This incompetence causes a stasis in the pulmonary circulation, and therefore hypertrophy develops in the walls of the right ventricle due to increased work. Riegel points out that pure mitral stenosis has an entirely different influence; he says that it causes dilatation and thickening of the walls of the left auricle; but the walls of the left ventricle, when the stenosis is not accompanied by any incompetence, are neither stretched nor thickened, but, on the contrary, changed in the opposite direction, viz., in the direction of concentric atrophy. But, as we know, stenosis and incompetence are generally associated and we find the walls of the left ventricle hypertrophied, both with disease of the mitral valves and with changes in the semilunar (aortic) valves.