E-text prepared by Robert Shimmin, Carol David, Joshua Hutchinson, and the Project Gutenberg Online Distributed Proofreading Team Note: Project Gutenberg also has an HTML version of this file which includes the original illustrations. See 15283-h.htm or 15283-h.zip: (https://www.gutenberg.org/dirs/1/5/2/8/15283/15283-h/15283-h.htm) or (https://www.gutenberg.org/dirs/1/5/2/8/15283/15283-h.zip) DISEASE AND ITS CAUSES by W. T. COUNCILMAN, A.M., M.D., LL.D. Professor of Pathology, Harvard University New York Henry Holt and Company London Williams and Norgate The University Press, Cambridge, U.S.A. 1913 PREFACE In this little volume the author has endeavored to portray disease as life under conditions which differ from the usual. Life embraces much that is unknown and in so far as disease is a condition of living things it too presents many problems which are insoluble with our present knowledge. Fifty years ago the extent of the unknown, and at that time insoluble questions of disease, was much greater than at present, and the problems now are in many ways different from those in the past. No attempt has been made to simplify the subject by the presentation of theories as facts. The limitation as to space has prevented as full a consideration of the subject as would be desirable for clearness, but a fair division into the general and concrete phases of disease has been attempted. Necessarily most attention has been given to the infectious diseases and their causes. This not only because these diseases are the most important but they are also the best known and give the simplest illustrations. The space given to the infectious diseases has allowed a merely cursory description of the organic diseases and such subjects as insanity and heredity. Of the organic diseases most space has been devoted to disease of the heart. There is slight consideration of the environment and social conditions as causes of disease. Very few authors are mentioned in the text and no bibliography is given. There is lack of literature dealing with the general aspects of disease; the book moreover is not written for physicians, and the list of investigators from whose work the knowledge of disease has been derived would be too long to cite. It has been assumed that the reader has some familiarity with elementary anatomy and physiology, and these subjects have been considered only as much as is necessary to set the scene for the drama. I am indebted to my friend, Mr. W. R. Thayer, for patiently enduring the reading of the manuscript and for many suggestions as to phrasing. CONTENTS CHAPTER PAGE CHAPTER I