It will be necessary now to examine more in detail the special characteristics of the several regions of South Africa and their relative fitness for receiving patients and visitors. Besides the question of climate many other factors must be considered, such as the accommodation for invalids, the possibility of obtaining comfort and suitable food, and the social conditions which form, from a psychological standpoint, an important element in the treatment. To take the last point first, I would earnestly deprecate the focal accumulation of a large number of invalids, especially of tubercular invalids, in one centre; not so much because of the infectivity of such an accumulation, but because of the deplorable mental depression which results from the constant contemplation of other sufferers from this disease. Any one who has had experience of large hospitals or sanatoria for phthisis must have been struck with the undesirability, from this point of view, of the aggregation of patients. Mind and body are so inextricably mingled that the intelligent physician will attach not less importance to factors concerning the first than to those affecting the second. Let the sick man, therefore, avoid his sick fellows, when this is possible, and mix by preference with the healthy and robust. Health, like ill-health, is contagious. But when the patient's forces are too far shattered to allow of this, sanatoria become necessary. I contend still that these should be small and disseminated, rather than central and on a colossal scale. This subject will be discussed in greater detail later.