Degree of Its Heat-abstracting Capabilities-Influence of Tempera- ture, Humidity, Wind Movement-Variability of Heat-dissipation- Diminished Atmospheric Pressure-Influence of Altitude upon Red Blood-corpuscles, Blood-pressure, Respiration, Nervous System- Necessity for Individualization-Clinical Testimony Regarding the Value of Climate-Inconsistency of Opponents-Cases Appropriate for Climatic Change-Four Distinct Classes-Cases Inappropriate for Climatic Change in General-Considerations Relative to Climatic Selection-Importance of a Discriminating Choice of Climate According to the Physiologic Adaptation of the Individual-Contra- indications for Residence in High Altitudes-Cases Suited to Low Temperature with Varying Degrees of Moisture-Popular Localities. TREATMENT OF SPECIAL SYMPTOMS. Cough-Extraordinary Differences of Character-Divergence of Therapeutic Indications-Local Causative Factors-General Con- stitutional Disturbances-Detailed Hygienic Measures-Subjective Control on the Part of the Individual-Digestive Disorders: Dietetic and Medicinal Management-Organic Disturbances: Functional Neuroses-Night-sweats: Hygienic Measures-Insomnia: Attention TREATMENT OF PULMONARY HEMORRHAGE General Considerations-Modifications of Treatment According to Intelligent Interpretation of the Significance of Clinical Manifesta- tions-Therapeutic Management-The Initial Directing Influence of the Physician-Attention to Vitally Important Details of Manage- ment and Environment-Rational Employment of Selected Drugs- Routine Administration of Drugs Productive of Very Injurious Effects-Prevailing Tendency to Decry the Value of all Medication- Protest Against this Popular Fad-The Intelligent Exhibition of a Few Remedies Constitutes a Valuable Adjuvant to More Important Historic Review-The Employment of Tuberculin-Inoculations With Living Attenuated Tubercle Bacilli-Maragliano's Method- 726-738 739-762 763-778 PULMONARY TUBERCULOSIS PART I ETIOLOGY AND PATHOLOGIC ANATOMY SECTION I GENERAL ETIOLOGIC CONSIDERATIONS CHAPTER I INTRODUCTION In a work devoted essentially to the clinical aspects of pulmonary tuberculosis it is manifestly impossible to dwell at length upon features of a purely bacteriologic nature, although they constitute data of enormous interest in connection with the general subject of tuberculosis. A vast amount of scientific work has been performed by enthusiastic students during the quarter century since the discovery of the tubercle bacillus by Robert Koch. The results of their labors have been of tremendous value from the standpoint of scientific investigation, and of vital importance in the elucidation of practical problems pertaining to the etiology of this disease. Their patient toil in the realm of animal experimentation and of laboratory research has been productive of such a mass of absorbing medical literature as to preclude more than its cursory mention even were this book limited solely to a historic review of the progress achieved along these lines. Much less, then, is detailed reference permitted to the innumerable contributions of the many workers in the field of scientific study, the sum-total of whose observations is of such infinite magnitude. A volume of enormous proportions is needed to accord justice and honor to the noble work of the earlier students. It would, indeed, be a Herculean task for one not especially trained. in the technic of laboratory methods nor fully conversant with the intricate details and scope of previous investigation to attempt in review an elaborate exposition of the achievements of individual students during the slow evolution of our present knowledge concerning the etiology of tuberculosis. There is disclaimed any original scientific study or profound knowledge of the special departments relating to bacteriologic or histologic research. There will be no attempt to introduce contributions of this nature nor to advance unsustained personal opinions concerning the proper interpretation to be placed upon the reported results of exper imental work by others. In such purely technical matters it is hoped to voice, as far as possible, the consensus judgment of those who are qualified by experience and equipment to form rational conclusions. Elaborate scientific treatises abound which present in detail the results of individual observations concerning the tubercle bacillus and the many aspects of infection. The large and comprehensive volume by Straus upon the bacillus alone is an example of the stupendous amount of literature extant in relation to features of etiologic interest. An effort will be made in this connection merely to review the more practical and essential etiologic facts without undue consideration of the various theories as yet incapable of complete verification. HISTORIC REVIEW Tuberculosis is, beyond question, the most important disease with which the human race has ever been obliged to contend. Its antiquity dates from the earliest records accessible to man. The writings of Hippocrates, 460 to 377 B. C., contain a description of the disease so correct in its essential details as to equal a work of modern excellence. From the period of Galen, 200 B. C., until the present time widely divergent conceptions have been entertained as to the pathology of consumption, but a uniform opinion has prevailed relative to its clinical characteristics. Only in comparatively recent years, however, has belief in its curability become general. Recognition of nodules or tubercles in the lung was obtained about the middle of the seventeenth century. Upon beginning anatomic investigation and with the discovery of cavity formation and pus collections numerous conjectures were offered as to the pathogenesis of the disease. The first efforts toward inoculation experiments were made in the early part of the nineteenth century, and were not attended with clearly definable results. Consequently there was much speculation concerning the possible infectiousness or transmissibility of tuberculosis. Laennec contributed much to the knowledge of the disease by establishing a more definite relation between tubercles and consumption, and by advocating the identity of pulmonary and glandular tuberculosis from a pathologic standpoint, although the specific microorganism, of course, was unknown. Rokitansky was an exponent of the same doctrine, but insisted upon the significance of a certain adaptability or susceptibility to consumption, as evinced by a peculiar type, or "phthisical habitus." Virchow cleared the atmosphere to some extent by expounding the pathologic and histologic structure of tubercle. Microscopic research had been undertaken previously by Lebert, who described the so-called "tubercle corpuscle' as a nonnucleated cell in the midst of tubercle formation. The first experimental evidence of the inoculation transmission of the disease was furnished by Klencke in 1843. He inoculated rabbits with tuberculous material, and at autopsy, twenty-six weeks later, found disseminated tubercle deposit in the liver and lungs. In 1857 Buhl promulgated the doctrine of the origin of miliary tuberculosis as a result of the distribution, through the medium of the circulation, of an agent derived from an area of infection within the body. Villemin in 1865 conducted a series of inoculation experiments of the greatest value. In addition to introducing into animals an infective material obtained from tuberculous tissues and the sputum of consumptives, he injected into a second class non-tuberculous pus, and in a third, the caseous matter from tuberculous cows. A tuberculous deposit was found after the introduction of purely infective matter from any source, confirming the theory of the specific infectious nature of the disease. An apparent identity of human and bovine tuberculosis also was suggested by the demonstration of tuberculous changes in all instances irrespective of the derivation of the infective agent. Despite vigorous opposition and conflicting results of animal experimentation by others, belief in the correctness of Villemin's conclusions became established upon a firm basis through the supplemental experiments of several observers. Among these, Cohnheim contributed prominently to the acceptance of Villemin's teaching by his method of inoculation into the anterior chamber of the eye of a rabbit. By this means opportunity was afforded for visual inspection of the gradual development of pathologic change. The discovery of the specific microorganism in tuberculous tissues and its etiologic relation to the development of the disease in man and lower animals was made by Robert Koch in 1882. By an original method of differential staining he succeeded. in isolating the tubercle bacillus and showed its presence in infected areas in all parts of the body. Previous to this, characteristic tubercle formation had been recognized in the scrofulous affections of glands, bones, and joints, although the precise infective agent had not been discovered. Koch demonstrated the absence of tubercle bacilli in other than tuberculous conditions, and even accomplished the successful inoculation of animals from pure artificial cultures of tubercle bacilli after the elimination of all extraneous elements and the removal of accessory sources of error. Koch thus established the cause of tuberculosis among man and animals by the discovery of the bacillus and the results of inoculation experiments. The apparent etiologic identity of all forms of tuberculosis in different species was determined also upon the basis of the characteristic histologic structure of the primary tubercle. Since this time a mass of evidence has been presented by numerous observers both for and against the acceptance of essential differences. in the cultural characteristics, virulence, and powers of transmission of the bacillus in the several animals in which a natural habitat is found. Despite a degree of similarity of the clinical manifestations in different species, important differences, referable to the bacillus of various types have been noted and will be the subject of future discussion. The tubercle bacillus of human origin is of more essential present interest. CHAPTER II THE TUBERCLE BACILLUS In view of all that has been written of this microorganism, attention will be called merely to a few of its more important features. The tubercle bacillus is a small, immobile rod of somewhat varying size and shape. The average length has been described as from one-fourth to one-half the diameter of a red blood-corpuscle. Differences in length, however, are found to exist in accordance with the virulence of the |