In acute pulmonary tuberculosis and in certain derangements of the nervous system, it is generally admitted that the rest regimen is a success. This treatment requires complete relaxation, both mental and physical, and any influence which causes increase in the cardiac effort constitutes exercise and is the antithesis of rest. In order to secure the maximum amount of rest, something more than being confined to bed is required. Apprehension, worry and mental depression act as physical stimulants, while emotions caused by noise, anger and arguments upset the vasomotor equilibrium and defeat efforts employed to obtain this form of treatment. The patient should therefore be freed from all responsibility, quietness assured, and a pleasant, cheerful and optimistic environment established. When dealing with a severe infection, such as the acute stage of empyema, rest is imperative. Following the active phase, the inflammatory process in the pleura becomes localized, a pyogenic membrane forms,