CHAPTER I. Uses of Classification in the Study of Disease; Comparison of (Part 1)

CHAPTER I. Uses of Classification in the Study of Disease; Comparison of Physical and General Signs 3 3 8 CHAPTER IL. Conformation of Chest; Circumstances influencing it; Mode of Examination; Mensuration; Succussion . CHAPTER Il. Percussion; Rationale ; Mode of Performing; Pleximeter; Divi- sion of Chest into Regions ; Value of Percussion CHAPTER Iv. Auscultation ; Modifications of Respiration and Voice ; Bronchial Respiration, Cavernous, Amphoric, Rude. Signs of the Voice, Pectoriloquy, Bronchophony . : : 4 CHAPTER V. Cough, Expectoration . . . . . Ww 27 36 76 14 . CONTENTS, CHAPTER VI. Pleurisy ; Pathological Anatomy ; Physical Signs; Symptoms; Diagnosis; ‘Treatment . : : . 8 CHAPTER VIL. Bronchitis ; Acute Varieties ; Signs and ‘Treatment of Acute Va- rieties ; Bronchitis of the Old; Chronic Varieties; Peculiar Varieties P 9 a ¢ 2 5 115 CHAPTER VIII. Dilatation of the Bronchial Tubes. : . . 143 ° CHAPTER IX. Emphysema of the Lungs; Anatomical Characters ; Symptoms ; Diagnosis; Prognosis; 'I'reatment —. 7 . M6 CHAPTER X. Asthma; Nervous Asthma; False Asthma; Paroxysms; Diag- nosis; Treatment ; : : . 152 CHAPTER XI. Pneumonia; Anatomical Characters; Physical Signs; Symp- toms; Treatment; Varieties . . 5 . 157 CHAPTER NII. Gangrene of the Lungs; Pathological Lesions; Symptoms; Causes; Diagnosis; ‘Treatment . . . 189 CONTENTS. 16 CHAPTER XI. Tuberculous Phthisis; Nature of the Disease ; Anatomical Cha- racters; Mode of Attack ;~Causes; Symptoms ; Physical Signs; Diagnosis; Prognosis; Treatment. 195 CHAPTER XIV. Pneumothorax ; Anatomical Characters ; Symptoms and Physical Signs ; Diagnosis and Prognosis ; Duration and Termination ; Treatment . : 5 . . . 255 CHAPTER XV. Pulmonary Hemorrhage ; Division into Varieties ; Mode of Attack ; Symptoms; and Physical Signs ; . . 262 CHAPTER XVI. Tubercles of the Bronchial Glands ; Diagnostic Characters ; Treat- ment. . 3 “ 5 . . 267 DISEASES OF THE HEART. CHAPTER XVII. General Considerations : 4 . é . 269 CHAPTER XVII. Pericarditis ; Anatomical Characters; Physical Signs; General Symptoms; Prognosis; Causes; Treatment . 4 287 16 CONTENTS. CHAPTER XIX. Endocarditis; Anatomical Characters; Symptoms; Diagnosis ; Treatment . . . . 5 . 297 CHAPTER XX. Hypertrophy of the Heart; Varieties; Anatomical Characters ; Causes; Signs and Symptoms; Progress and Termination ; Treatment . 5 5 . 2 . 305 CHAPTER XXI. Dilatation ; Anatomical Characters; Causés; Symptoms; Diag- nosis and Prognosis; Treatment 4 . : 316 CHAPTER XXII. Diseases of the Valves ; Nature of the Disease; Signs and Symp- toms; Diagnosis; Treatment . . . + 820 CHAPTER XXIII. Functional Diseases of the Heart; Palpitation; Pain ; Intermit- tence; Angina Pectoris P 2 3 2 332 CHAPTER XXIV. Diseases of the Aorta; Aortitis; Anatomical Characters ; eyele toms; Diagnosis; Prognosis; Treatment 3 336 CHAPTER XXV, Aneurism of the Aorta; Anatomical Characters; Symptoms; Diagnosis; Treatment . ; 5 é : 340 Spirometer, notice of : F : . . 845 DISEASES OF THE CHEST. "CHAPTER I. USES OF CLASSIFICATION IN THE STUDY OF DISEASE—COMPARISON OF PHYSICAL AND GENERAL SIGNS. Iy the study of diseases of the chest, as well as those of other cavities of the body, the classification adopted for the conve- nience of the pupil must often be arbitrary and imperfect. Dis- eases which are naturally closely connected together, are sepa- yated into artificial subdivisions, while others which are essen- tially dissimilar are brought together in a manner which tends to lead the mind of the pupil from the study of their true rela- tions; still, the artificial divisions which have been admitted for a long time, are in general the most easily recollected, and for purposes of study possess many advantages; while the erroneous conclusions to which an artificial classification some- times leads may be obviated by attention to real points of simi- larity, and the natural connection may finally be re-established after it has been for a time broken up. There is thus a double task for the author or teacher: first, that of analysis, for the purpose of discovering and pointing out isolated facts; next, that of synthesis, or of bringing together those which present, in common, strongly marked fundamental characters. Both of these tasks must be kept in view, or the true scientific connec- tions of disease may be forgotten, and the diagnosis will be merely local, and therefore imperfect, instead of being based on correct and enlarged data. The very division of diseases into those belonging to the 2 18 USES OF CLASSIFICATION. several cavities of the body, is, in a great degree, artificial; and although many of these affections are strictly local, or nearly so, there are others which are nothing more than evident shoots from a diseased root, which extends itself widely throughout the body. In these cases the disease, when it shows itself in the chest, is readily recognised, and is taken as a sign of the general disorder. Sometimes the local disorder grows rapidly, and be- comes the prominent malady; but in all such cases it is only a sign of a deeper and more extended mischief. The remarks which are applicable to the study of disease, are naturally extended to the means of discovering it. These are separated according to the various methods of investigation re- sorted to, whether founded on the general symptoms or the phy- sical changes of the part; and they are more or less deceptive without a careful comparison, or collation of them, one with an- -other. This is not done by a smatterer in pathology or in diag- nosis; hence, the conclusions attained by him are uncertain, and cast discredit upon medicine, and especially on exact diagnosis. The rules of true philosophy, as applied to medicine, do not differ from those of any other science. The same mental discipline, and the same rules of philosophising are required; and, with equally ascertained data, the same degree of certainty may be attained. We must first separate a group of facts into detached elements, examine them in every practicable way, and then bring them together again, and reinstate them in a regular and natural order. In all departments of science, especially the natural sciences, with which medicine is so closely connected, we examine the ob- jects of our research in two ways: first, as actually existing; and, secondly, as past. The objects actually present, are known by evident signs; those past, are discoverable by the more obscure traces which they have left behind. We thus discern the modes of a disease, just as we learn the habits of a plant or an animal, from its footsteps, or the remains of its food; and we ean, in either case, learn the peculiarities which have charaeterized them during life, or during the continuance of the diseased action, by phenomena actually occurring, or the changes consequent upon them. We are therefore obliged to discriminate in the study of GENERAL AND PHYSICAL SIGNS. 19 disease, between those phenomena which are actually going on, and those which have terminated and are no longer of mischief; this obyiates many grave errors, and prevents a disorder from being confounded with the lesions which often constitute the proof of its cessation, or it prevents us from mistaking the actions which are in their nature mischievous, for those which are use- ful and salutary. The latter error is one of more frequent oceur- rence than the former, for the severe diseased action may require for its removal a’slighter, but more. permanent deviation from the healthy functions of the part. And although this secondary disorder would, if occurring singly, constitute a disease, it ceases to be one when it is merely a curative agent which exerts a favour- able influence with the primary affection. These diseases are often very similar to blisters, or other powerful revyulsive means, truly curative, and they then only become injurious when heed- lessly meddled with. The recognition both of the primary and secondary disorders, is more easy in affections of the thorax than in those of other cavities of the body, from our possessing the advantage of two distinct modes of investigation. These are the altered functions, including both those of the viscera of the thorax and of the rest of the body, and the physical signs offered by the diseased organ. The general symptoms of thoracic diseases are learned in the same way as those of other organs of the hody; but the physical signs, on the other hand, are so much more applicable to chest affections than to any other disorders, that they are, in practice, with a few exceptions, used only in the diagnosis of the diseases of this cavity, and are generally described with direct reference to the chest. This peculiar fitness of the physical signs for the study of pectoral diseases, depends upon the conformation of the thorax and the structure of the organs contained within it. These are important viscera,—the lungs and heart, which are organs possessing different degrees of density, and constantly in motion ; so that certain sounds are produced which serve to distinguish the healthy from the diseased action. Ilence we may, from the examination of the thorax, not only ascertain the density of the organs when at rest, but we may, with great certainty, discover whether they act in a regular and natural manner, and what im- 20 GENERAL AND PHYSICAL SIGNS pediments interfere with their motion. These advantages are not offered by the viseera of any other eavity; for although the physical properties of them are sometimes sufficiently marked to enable us to deteet variations in form, or in density of tissue, they are seareely ever susceptible of sufficient motion to eause an audible sound by their own contraction, or by the passage of afluid throughout their cavity. The physical signs are, therefore, chiefly adapted to the investigation of diseases of the thorax Physieal exploration is mueh more extended in its applieation when combined and compared with the rational signs, than if used alone. For in itself it teaches us rather the condition of organs as modified by disease, than the manner in which the dis- ease forms, or the mode in whieh it advances. This is especially the ease in the ehronie diseases of the chest, which depend upon a general viee of the economy, for in order to distinguish disease from health, by the physieal exploration of the lungs and heart, it is necessary that a ehange should oceur in the strueture of the tissue,—and as this alteration is only brought about slowly and gradually, we cannot always deeide whether the tissue is or is not diseased to some extent; if it be diseased in a degree not sufficient to produee an important change in the eonformation of the part. There is, therefore, no means of arriving to a eorreet conelusion in the diagnosis of pectoral diseases, other than a union of the two modes of investigation, whieh will then work together as two different ways of arriving at the same end. When physical exploration is properly understood, and compared with the symptoms, it will be found to be even more useful for its negative than its positive results ; that is, it will be more useful asa means of showing that some diseases do not exist, or that a given disease has not arrived at a point of structural disorganization suf- ficient to endanger life, than as direet evidence of the mischief already done to the organs. The positive evidence derived from physieal exploration is so simple and easily diseovered, that after acquiring a certain familiarity with it, little attention is required to diseover the full value of the signs: the negative evidenee, on the other hand, is much more diffiewlt—for a thorough knowledge of the means of examination, and much practice in using them, are required to pronounce with certainty as to the existence of GENERAL AND PHYSICAL SIGNS. 21 slight alterations of a part, or the absence of decided structural change. But when the necessary familiarity is acquired, the certainty of the knowledge obtained from this source is such, that we may rely upon the negative evidence as confidently as upon the positive signs, especially when compared with the indications derived from general symptoms. The great value of the negative evidence of physical explora- tion depends upon its certainty. The process of reasoning which renders negative evidence of value in diagnosis, is called reason- ing by way of exclusion; but, although it is of great utility when skilfully applied, it is useless unless a disease is announced by positive signs when it exists, and then we may look upon the absence of these signs as a proof that it is not present. If, on the other hand, the signs themselves be doubtful, the absence of them is of course no proof that the disease does not exist; or if these signs be of such nature that we can ascertain them with extreme difficulty, they lose the advantage of serving both as negative and positive evidence. Now, in the diseases to which physical exploration is applicable, this is not the case. The signs are, in general, very easily ascertained, and are always, under similar circumstances, the same; hence they may be used in the way of exclusion with great confidence; that is, when they are not discovered by one who is familiar with the means of explor- ing them, they may be confidently said not to exist. This nega- tive evidence, as I have already stated, is useful in two ways: first, as evidence that there is no disease at all existing; secondly, as evidence that there is no great change of structure. The first requires that the general symptoms should agree, as it were, with the physical signs, in proving the integrity, or the comparative soundness of the part. ‘The second requires that the physical signs should be, to a certain extent, contradicted or disproyen by the general symptoms. But, as this seeming discrepancy is applicable only to the degree of the alteration, and not to its nature, there is, in fact, no real contradiction between the two means of examination. On the contrary, they will be found, when compared together, to accord singularly in the principal deductions which are drawn from each of them. The extent of application of the physical means of exploration 22 GENERAL AND PHYSICAL SIGNS. is, perhaps, novel to many persons who are not familiar with the beautiful application of the laws of diagnosis, by way of exclu- sion, in which the certainty of the physical signs renders them even more useful, than in other cases in which a precision ap- proaching to mathematical correctness is required; but this very certainty may render them an occasional souree of error with those who are neither accustomed to their use, nor perfectly familiar with the ordinary symptoms of disease. That is, an art which is evidently based upon fixed physical laws, may lead to error when the data upon which the problem of diagnosis is founded are not perfectly settled, although the process of reasoning may still be the correct one. But, the abuse of a certain method of observation does not constitute a real objection to its employ- ment; it merely proves that it is necessary tosurmount the first difficulties which attond its acquisition: The great importance of the comparison of the general symp- toms and physical signs has become more apparent with the more habitual employment of phy: jon, as a really prac- tical aid to diagnosis. The earlier writers on auscultation, espe- cially Laennee, were rather disposed to separate physical from symptomatic diagnosis: this error depended upon the novelty of the art, and the overstrained efforts to extend its application, — but as physicians became more familiar with it, and had oppor- tunities for testing its merits, it was placed on its real footing, and regarded as more useful than any symptoms taken singly, but as neither the only class of symptoms to be relied upon, nor as superseding the general signs. Weare indebted tothe French pathologists for pointing out the necessity of comparison of all the symptoms of pulmonary disease, and of connecting this com- ion in order. It is a subject largely parison with their sueces insisted upon in the writings of Andral, but one which was most completely developed in the lectures of Dr. Louis. It afterwards received much attention from Dr. Stokes, and others, who have occupied themselves with the study of pectoral diseases. Although it is not at this time necessary to insist upon the truth of the physical signs to those who are conversant with their use, their certainty may still appear questionable to a few who are not practically acquainted with them. As these signs are GENERAL AND PHYSICAL SIGNS. 23 based upon the settled laws of physical science, and in fact involve some universally admitted principles, the only reason for doubt- ing their accuracy is a want of due knowledge on the subject. But as a certain acquaintance with them is necessary to appre- ciate the evidence upon which they depend, I may properly enough point out what is included under the terms physical exploration and physical signs. Physical exploration includes the modes of ascertaining the changes which occur in the physical structure of organs; these changes we appreciate by the alterations of form, and by the sounds produced in the interior of the body by the motion of solids, or of elastic or non-elastic fluids, or by the resonance which is yielded by the surface when tapped or struck by the finger. This latter mode of examination obviously depends upon the different density of organs, and in the cavity of the thorax, chiefly upon the existence of air, so that the percussion is more or less clear or dull, as the quantity of air contained within the thorax is greater or less. The alterations of form are few in number, and are readily learned; but the signs dependent upon changes in the