It would be easy, by pursuing this subject a little further, to mention a number of facts which, by the aid of principles in physiology and pathology, which are universally admitted, would open to us a new theory of fevers, but this would lead us too far from the subject before us. I shall only remark, that all that has been said of the influence of _general_ debilitating causes upon the lungs, both in pneumony and consumption, and of the alternation of the consumption with other general diseases, will receive great support from considering the lungs only as a part of the whole external surface of the body, upon which most of the remote and exciting causes of both diseases produce their first effects. This extent of the surface of the body, not only to the lungs, but to the alimentary canal, was first taken notice of by Dr. Boerhaave; but was unhappily neglected by him in his theories of the diseases of the lungs and bowels. Dr. Keil supposes that the lungs, from the peculiar structure of the bronchial vessels, and air vesicles, expose a surface to the action of the air, equal to the extent of the whole external and visible surface of the body. Thus have I mentioned the usual palliative remedies for the consumption. Many of these remedies, under certain circumstances, I have said have cured the disease, but I suspect that most of these cures have taken place only when the disease has partaken of an intermediate nature between a pneumony and a true pulmonary consumption. Such connecting shades, appear between the extreme points of many other diseases. In a former essay[31], I endeavoured to account for the transmutation (if I may be allowed the expression) of the pneumony into the consumption, by ascribing it to the increase of the debilitating refinements of civilized life. This opinion has derived constant support from every observation I have made connected with this subject, since its first publication, in the year 1772. [31] Inquiry into the Diseases and Remedies of the Indians of North-America; and a comparative view of their diseases and remedies with those of civilized nations. Vol. I. I come now to treat of the RADICAL REMEDIES for the pulmonary consumption. In an essay formerly alluded to[32], I mentioned the effects of labour, and the hardships of a camp or naval life, upon this disease. As there must frequently occur such objections to each of those remedies, as to forbid their being recommended or adopted, it will be necessary to seek for substitutes for them in the different species of exercise. These are, _active_, _passive_, and _mixed_. The _active_ includes walking, and the exercise of the hands and feet in working or dancing. The _passive_ includes rocking in a cradle, swinging, sailing, and riding in carriages of different kinds. The _mixed_ is confined chiefly to riding on horseback. [32] Thoughts on the Pulmonary Consumption. Vol. I.