phthisis in the first stage. The arterial systolic bruit of the first stage of phthisis is seldom perfectly uniform, even when it is continuous. It rises and falls in intensity with the force of the heart's action. When the heart is excited the sound becomes heightened, and when the cardiac contraction is reduced in force, the bruit is lowered. At least this variation is found in most examples. In not a few persons in whom this physical sign is heard, it disappears, or altogether fails to be heard, for a time. Thus after having been heard very distinctly, the utmost attention will fail to detect it a few hours after. I have sometimes been disappointed with this silence, for it caused me some doubt as to the accuracy of my first examination. But I soon learned that the silence of one day did by no means argue the absence of sound on a previous occasion. The silence or the absence of the arterial bruit, after it had been distinctly heard, has been due to reduced force of the cardiac contraction. The sound has been got rid of by quietude, and it has generally been reproduced by sharp walking in a room. This non-persistence is valuable in diagnosticating this sign, the result of phthisis from that occurring in arterial obstruction. The disappearance is more common in phthisis than in valvular disease. Taken by itself this arterial sign is of no diagnostic value in the first stage of phthisis; and associated with other signs that are conclusive, it is confirmatory, but it is also almost always superfluous in the diagnosis. It is just possible that in some very rare examples a marked arterial systolic bruit proceeding from the arteries may be present from the pressure of tubercle in the lung, immediately and exclusively in the vicinity of the arteries when the percussion note may be little affected; but such a coincidence must be rare, and it would be unsafe to rely much upon it. Occurring by itself, then, an arterial whiff is by no means conclusive of the presence of tubercle; it may be held to justify some suspicion, and to suggest further watching and renewed exploration. If associated with loss of weight and obscure hectic symptoms, the explorations should be more frequently repeated and the more rigidly performed. The mechanism of the arterial bruit is this. The tubercle presses upon the artery, causes the walls to come in more than usual collision with the moving column of blood, and more than the usual sound is produced. Besides this, another cause is in operation in most examples: the heart's contraction is preternaturally excited, and the column of blood is thrown with more than the usual violence along the arterial channel. The obstruction in the channel is reinforced by the additional force of the

current, and thus another element in the production of sound. is added.

The loudness of the sounds of the heart is another early sign in phthisis. In a large proportion of cases of this disease, even in the first stage, the stethoscope placed under the clavicles seems to convey to the ear the sounds of the heart in an exaggerated manner, or in a louder tone than is natural. The impression made upon the ear serves to convey the idea that the heart is preternaturally near, and that the action of that organ is unduly excited. At all stages of the respiratory act this increased intensity is observed.

Unless supported by

The value of this sign is not great. tubular breathing, dry crackle, very long expiration, shortness or dullness of the percussion sound, it would be extremely dangerous to rely much upon it as evidence of phthisis in the first stage. One or more of these signs are essential to give it any positive value as a sign of phthisis. All of the signs referred to are not necessary; but one or more are for this purpose. When cardiac loudness is found alone, and when the action of the heart is not greatly excited, and when the body of the patient is slowly wasting, and when cough, though very moderate, and some continuous shortness of breath are present, preternatural intensity of the heart sounds, though not conclusive of the presence of incipient phthisis, is not to be held worthless, but justifies the suspicion that this disease is present.

In the case of nervous patients with rapid pulse this sign is still less reliable. But the presence of it in nervous patients is not to be altogether disregarded; for nervousness and phthisis may, and often do, co-exist. To give it value in such patients the presence of the other confirmatory signs above noted is the more necessary. This sign acquires a degree of value when it is confined to the right side.

The mechanism of the increased intensity of the heart's sounds in the first stage of phthisis appears to be this: the greater density of the lung increases the property of receiving sound from solid bodies, such as the heart; and a solid body in sonorous modulation, such as the lung, moderately tuberculated, is better calculated to convey its sonorous undulations than an aeriform body, or a comparatively aeriform body, such as the fully vesicular lung, to another solid body, such as the walls of the chest. It is doubtless true that solid bodies bestow their sounds freely upon aeriform bodies, but it is also true that by the looseness of the particles of such bodies, and by the diffusion in all directions of air, under ordinary circum

INCREASE OF LOUDNESS.

109

stances, sound is soon dispersed and sensorially lost. When air is confined in a tube after receiving sound from a solid body, the sound is maintained in very considerable intensity, and may be conveyed a great distance. In the acquisition by a solid body of sound from another solid body, an element in the production of the phenomenon is the weight with which it presses upon the body from which it borrows sound. The weight of the body offers a resistance to its displacement in the mass or lump, and exposes its particles to the molecular motion which is essential to sound, and, indeed, upon which sound depends. Wood lightly placed upon a sounding body, such as a musical box, accepts sound much less fully than wood that is applied with a moderate degree of pressure or force. It is true, however, that much weight, on the other hand, may prove unfavourable to the acceptance and conveyance of sound, for this weight may interfere with and impede the sonorous vibrations of the sound-communicating body; or, in other words, the force of the original sounding body may not be sufficient to throw into molecular motion the heavy superincumbent body. This may be proved by placing rods of wood of different densities upon a musical box. The very light wood conveys less sound than the more heavy; but if a heavy iron rod be employed, the sound that is communicated is again reduced, the weight of the iron impedes the movements of the musical box, and the iron is too heavy and resisting to be thrown into the full vibration of wood by the sounding instrument. We have much the same thing produced in auscultation of the chest: lung that is moderately dense, as from the presence of tubercle, conveys sound well; but if very hard and very dense, and the originating soundbody be feeble and easily restrained in its molecular motion, such as the flaccid heart, the sound is feebly conducted, and is sometimes inaudible. This will serve to explain the conflicting facts which have been observed in relation to sound and consolidated lung. Sometimes the sounds have been found feeble, and at other times they have been found to be increased in intensity. In all cases there has been consolidated lung; but in reference to the sounding body, it has been sometimes, from great density, opposed to acceptance and conduction, while it has been at other times favourable to acceptance and conduction, from lesser density and lesser resistance. Resistance to some extent is necessary for the acceptance of sound; but resistance beyond a certain amount. and proportion may be fatal to this office. When the lung is moderately solidified by tubercle, it will come in contact with

the heart with more force and weight than finely vesicular lung, and will therefore accept sound more from that organ, in the same manner as the heavier piece of wood laid upon a musical box accepts sound, as has just been mentioned. If very heavy, the lung may impede the vibrations of the weak heart, and may even itself fail to be fully thrown into corresponding sonorous vibrations; and thus a deadening or damping effect may be produced, as in fact is sometimes observed. We have seen that hollow wooden and glass rods vibrate better than solid ones. Consolidated lung, such as the tuberculated structure, once in vibration will convey or propagate its movements to the solid walls of the chest and the solid stethoscope placed upon it better than fine vesicular lung, for this reason, that solid bodies, as has been before stated, are more suitable for propagating sound to solid bodies than aeriform bodies are. When bodies are neither wholly solid nor aeriform they maintain this characteristic in proportion to their solid or aeriform constitution. Lung with a moderate amount of tubercle, therefore, accepts sound and propagates it to solid bodies, such as the walls of the chest, better than vesicular lung or emphysematous lung.

ADVENTITIOUS HEART SOUNDS.-In the first stage of phthisis certain diseased conditions of the heart and great vessels are wont to be developed, and though their signs cannot be regarded as the primary signs of pulmonary consumption, yet they are in a manner signs of that disease, for it is to that disease the secondary disorders which they denote are referrible. They are truly signs of pulmonary consumption, but they are secondary signs. With this qualification, these signs are well worthy of some notice in this place.

The to and fro friction sound of pericarditis is occasionally heard in the first stage of phthisis. It occurs, for the most part, not until the original malady has continued some weeks or months. It is found chiefly in those examples of disease conjoined with pneumonia and pleurisy. The rheumatic, and those suffering from disease of the kidney, seem to be the most frequent sufferers. It is extremely probable that it is not uncommon in those subjects who are sufferers from deposit of tubercle in the kidney, and these are not a very small number.

Basic arterial murmurs have been occasionally heard by me in the first stage of phthisis; and from much post mortem exploration, I believe them, in a considerable proportion of cases, to have been due to the spreading of inflammatory action from the lung to the great arterial ostia, or to

ADVENTITIOUS HEART SOUNDS.

111

vitiation of the blood by the pulmonary disease doing the same thing, or to the direct deposit of tubercle in small yet visible amounts in the coats of these vessels. The murmurs which I have attributed to phthisis in this stage have been always systolic. The aorta has been much more the seat of this phthisical murmur than the pulmonary artery. The murmur is always persistent, and much the same during every part of the respiratory act, which is not the case with murmur originating in mere tubercular pressure already noticed. This form of murmur is usually accompanied with excited and tumultuous action of the heart, always persistent to a greater or lesser degree.

A venous humming at the thorax has been heard by me in a few examples of phthisis in the first stage. It has been heard over the seats of the innominata and the subclavian veins. It has been heard chiefly during inspiration. Sometimes it has been conjoined with venous murmur in the neck, but sometimes it has been found alone. It has not been peculiar to females. It is the single humming in the thorax that I have regarded as chiefly due to the presence of tubercle. It has always been found on the tuberculated In some cases hæmoptysis had taken place. Moderate pressure from tubercle has appeared to me to be the chief Anæmia has probably aided.

cause.

CHAP. XVII.

FIRST STAGE-continued.

General Character of thoracic Signs.-Signs of acute Phthisis.-Grouping of thoracic Signs in different Cases.- Duration of Signs.-Tendency to Progression. Occasional Subsidence, naturally and under Treatment.-Noncessation of Signs at Conclusion of first Stage.

THE thoracic signs of the first stage of phthisis are tolerably persistent. They are gradual in their development, and they seldom appear for a considerable time except in the society of each other in the chronic, and much the most frequent form of the disease. The roughness of inspiration is liable to some variation in degree; the more hurried the respiration is, the more rough is the respiratory sound. The length of the expiratory sound varies considerably, but it seldom disappears for a time. The subsidence of bronchial congestion, or of tracheal or laryngeal obstruction, is frequently followed