reader will be led to attribute the size of the book to the progress of knowledge pertaining to diseases of the heart, together with their intrinsic claims on the attention of the student and practitioner. A liberal share of the work is devoted to physical signs. But a just estimate of their practical importance will obviate any objection on this score. It is mainly owing to physical exploration that the study of these diseases has been prosecuted within the past few years with such remarkable success. Here, as in other classes of affections, the knowledge to be derived from clinical observation is increased in proportion to improvement in diagnosis, and it is evident that diseases cannot be judiciously treated unless correctly discriminated. The discrimination of diseases is confessedly the portion of our art which involves the most difficulty and calls. for the greatest amount of skill. Hence, it is especially under this practical aspect that diseases in general claim careful and extended consideration. This remark, certainly, is not less applicable to diseases of the heart than to other nosological divisions. And the diagnosis of cardiac diseases is for the most part based on the physical signs. It is, therefore, by no means solely because these are interesting, but on account of their great practical importance, that so much space has been accorded to them in the present treatise. In treating of the physical signs, it was necessary to introduce some matter belonging properly to anatomy and physiology, viz., the relations of the heart to the walls of the chest and the adjacent viscera, the movements of the organ, and the normal heart-sounds. With reference to the movements and sounds of the heart, the author has been led by examinations of the healthy chest to conclusions which appear to have important practical bearings. The abnormal modifications of the heart-sounds have hitherto scarcely received sufficient attention. More importance is attached to them as diagnostic signs, and they are considered more fully in this work than in any other on the diseases of the heart with which the author is acquainted. As regards the sounds of the heart in health and disease, some original views are introduced, which have entered into a previous publication.' In thus setting forth, briefly, the plan and objects of the work, the author assumes only to have spared no pains to render it On the Clinical Study of the Heart-Sounds in Health and Disease.-Transac tions of the American Medical Association for 1858. acceptable to the profession. All who have engaged in similar undertakings amidst the cares and distractions of active medical practice, will appreciate the difficulty of the task. But the time and labor which the author has bestowed upon it, will be more than requited by the approval of his medical brethren; and he is encouraged to hope for this reward by the favor with which his previous contributions to practical medicine have been received. The author would express his thanks to Prof. John C. Dalton, Jr., for the two illustrations which form the frontispiece, and for other friendly offices; also, to Dr. Austin W. Nichols, formerly assistant to the chair of clinical medicine in the University of Buffalo, for his valuable assistance in collecting materials for the preparation of the work. NEW YORK, September, 1859. CONTENTS. PAGE Altered situation and extent of the apex-beat in enlargement Increased force of the apex-beat and abnormal impulses in hyper- Increased size of the præcordia and abnormal movements in en- Symptoms and pathological effects referable to the circulation |