ON THE NATURE AND TREATMENT OF THE DISEASES OF THE ᎻᎬᎪᎡᎢ ; WITH SOME NEW VIEWS ON THE PHYSIOLOGY OF THE CIRCULATION; BY JAMES WARDROP, M. D. SURGEON TO HIS LATE MAJESTY, GEORGE IV.; LECTURER ON SURGERY, PREFACE. The First Part of this work contains Preliminary Observations on the structure and functions of the Heart, with which are interspersed some new Physiological Researches on the Circulation. The Second Part will give an account of the Diseases of the Heart, and those affections will be more especially treated of, which are of common occurrence, and which we have the means of alleviating by medical treatment,—but comparatively little will be said of those morbid changes which seldom occur, or over which the resources of medicine have been found to exercise little controul. Whilst prosecuting some investigations concerning the Diseases of the Heart, and more particularly regarding their causes and treatment, the author's attention was directed to certain symptoms with which various affections of that organ are accompanied, and, in seeking an explanation of them, he was led to reflect on several natural phenomena connected with the circulation of the blood in the Heart, and with the function of respiration, but of which no satisfactory explanation could be found, and to some of which even no allusion had been made in physiological writings. He was particularly struck with the influence of respiration on the action of the Heart, and with the influence of the action of the Heart on respiration, as well as with all the modifications of these functions, not only in diseases but likewise during the acts of weeping-sobbingcrying-laughing-in the giddiness experienced in turning round rapidly,-in swinging and in sea sickness. His attention was not less arrested when contemplating the influence, which the almost constant movements of the body exercise both on the respiratory and the circulating organs. He was led to enquire how the action of the heart and lungs is increased by violent exercise,—how persons can by a process of" training" acquire the power of using their muscles, until their muscular energy is exhausted, without causing breathlessness or a sense of suffocation,—in what the art of diving consists-and finally, how dis eases of the heart are caused by violent muscular exertions and by mental excitement. Having arrived at the conclusion, that these various phenomena are intimately connected with the great function of the circulation of the blood, further observations convinced the author, that each of these different acts is employed for performing a specific purpose in the economy,— some for increasing and others for diminishing the quantity of blood within the thoracic cavities, according as modifications in the quantity of blood are required, or an adjustment becomes necessary in different organs for the due performance of their respective functions. In pursuing these investigations, the mind was conducted step by step to establish the existence of three important functions,—functions connected with the circulation of the blood, which had hitherto been overlooked by physiologists. First, that the Muscles, besides being the active organs of locomotion, perform the important office of increasing the quantity of arterial as well as of venous blood, within the cavities of the heart. Secondly, that the Lungs regulate the supply of blood to the heart so as to prevent congestion within the heart's cavities; and Thirdly,—that the Subcutaneous Veins per |