always be made with positiveness. Examination of the chest by inspection will show restrained movements on the side to which the pain is referred; on percussion, there will be found to be no distinct disparity between the two sides, and on auscultation, the murmur of respiration will be more or less weakened on the affected side. But these signs are due to the fact that the pain leads instinctively to a diminished use of the lung on the side affected, while the use of the other lung is increased. These signs are equally present when the pain is incident to the affections from which this disease is to be discriminated. A slight friction murmur may be discovered in this stage; if distinctly present, its diagnostic significance is important; it shows that pleuritis exists, and the discrimination then lies between pleuritis as a primary disease or a complication of pneumonitis. To decide this point at once is not always easy. The diagnostic sign of pneumonitis, viz., the crepitant rale, if present, settles the question; but as this sign is by no means present uniformly in pneumonitis, its absence does not authorize the exclusion of that disease. The same remark is applicable to the characteristic expectoration of pneumonitis. It must be confessed that, in a certain number of cases, this differential diagnosis requires a little delay. But a friction murmur is heard in only a very small proportion of cases during the first stage, and, in the absence of this sign, the signs belonging to the second stage are essential to render the diagnosis positive.

The signs belonging to the second stage are usually present without much delay. If the disease be idiopathic pleuritis, after the lapse of twelve or twenty-four hours, liquid effusion will have taken place in sufficient quantity to be apparent. The signs now denoting the existence of the disease are those due to liquid effusion. The diagnosis is based upon these signs, in conjunction with the symptoms and history, and on the absence of signs of phenmonitis.

The signs of liquid effusion are obtained by percussion, auscultation, palpation, and inspection. On percussion, dulness or flatness is found at the base of the chest, extending upward in proportion to the quantity of liquid, the patient being in a sitting posture. The upper limit of the dulness or flatness corresponds to a horizontal line drawn across the anterior and lateral surface of the chest, this line denoting the level of the liquid. Changing the position of the patient to recumbency on the back, frequently induces a marked change in the relation of dulness or flatness and the resonance, as previously determined on the anterior surface of the chest, in the sitting posture; the liquid gravitating to the posterior part of the chest, the lung descends in front, and furnishes resonance for a greater or less distance below the line which was coincident with the level of the liquid while the patient was sitting. This latter test of the presence of liquid is not available in all cases. If the pleural surfaces above the level of the liquid be united by old adhesions, or agglutinated by lymph, the liquid and lung will maintain the same relation in different positions of the body. The failure of this test, therefore, is not proof against the presence of liquid. The test, however, is available, according to my experience, in a large majority of cases. The resonance over the lung above the level of the liquid, if it rise to a third, a half, or, perhaps, over two-thirds of the height of the ehest, is exaggerated, and acquires, in part, a tympanitic quality, constituting vesiculo-tympanitic resonance.

On auscultation, the respiratory murmur is either suppressed or feebly appreciable below the level of the liquid. Above the liquid, it is usually weak, as compared with the murmur on the opposite side. If the lung be considerably reduced in volume Ly the amount of liquid, the respiratory sound will become broncho-vesicular, or rude, and the vocal resonance will

be increased. If the liquid be sufficient to compress the lung into a solid mass, it will furnish the bronchial respiration. The bronchial respiration will be heard over the site of the compressed lung. It is usually limited to that site, but, in a certain proportion of cases, it is diffused over the greater part or the whole of the affected side. The normal vocal resonance is either suppressed or diminished over that portion of the affected side which corresponds to the space occupied by the liquid. But if the accumulation of liquid be large, bronchophony may be produced over the whole of the compressed lung, or at the portion in contact with the liquid. The bronchophony has sometimes a tremulous character, and is then ægophony. This variety of bronchophony is too rare to have much clinical value. If the chest be filled with liquid, bronchophony is sometimes diffused over the whole of the affected. side.

Vocal fremitus is usually either arrested or diminished by liquid effusion. From this fact is derived valuable evidence of the presence of liquid when the effusion is in the right pleural cavity, in consequence of the greater amount of fremitus over the right side in health. If the question be as to the presence of liquid in the right pleural cavity, and the fremitus be found to be greater on the left than on the right side, the evidence of liquid is strong.

If the quantity of liquid be large enough to distend the pleural sac, the intercostal depressions may be diminished or destroyed at the inferior, anterior, and lateral portions of the chest. This constitutes valuable evidence of the presence of liquid.

Other and marked signs of effusion are present if the quantity of liquid be sufficient to dilate the chest. This occurs exceptionally in acute pleuritis. It occurs much oftener in the chronic variety of the disease, and the signs referred to will be noticed in connection with the diagnosis of the latter.

The physical signs not only lead to a positive diagnosis after the first stage, but they show the amount of liquid in the pleural sac, a point of importance with reference to treatment. By means of daily explorations, the physician may ascertain whether the effusion be increasing or diminishing, and the rate of either the increase or diminution. The information thus obtained is highly important as a guide to the employment of therapeutical measures. This information cannot be obtained from the symptoms. The signs, therefore, are essential, not only to the diagnosis, but to a proper knowledge of the progress of the disease.

After absorption, to a greater or less extent, of the liquid, the pleural surfaces coming into contact over a larger area, and roughened by lymph which has now become dense and closely adherent, a friction murmur is frequently apparent. This is sometimes so loud as to be heard by the patient. It may continue into convalescence, ceasing when the pleural surfaces have become united by means of newly-formed tissue. A friction murmur, however, by no means occurs uniformly even at this stage of the disease.

PROGNOSIS. The prognosis in cases of acute, idiopathic, ordinary pleuritis is always favorable, provided the disease be uncomplicated, and the constitution of the patient be not enfeebled. There is reason to believe that, without therapeutical interference, it would very rarely prove fatal. have collected several cases in which this disease passed through its course favorably without any treatment. It may possibly prove fatal in consequence of a large amount of liquid effusion occurring very rapidly, death taking place by apnoea. I have known one instance in which the loss of a hospital patient, suddenly and unexpectedly, seemed fairly attributable to the fact that the pleural sac was greatly distended with liquid. Developed as a

sequel to other diseases, or in the course of a grave affection, such as Bright's disease of the kidneys, or in persons with broken constitutions, it may destroy life by asthenia. Acute pericarditis is sometimes developed simultaneously with, or during the progress of, pleuritis, and these associated diseases are apt to prove fatal. Their occasional coincidence is to be borne in mind, or the pericarditis, in this connection, if not carefully sought for, will be likely to be overlooked. As already stated, the development of pneumonitis, consecutively to pleuritis, is not to be expected, nor is there much, if any, danger that ordinary acute pleuritis, after its development, will eventuate in suppuration, constituting the variety of the disease called empyema. In short, the intrinsic tendency of the disease is to recovery, a fatal termination being due very rarely to the disease per se, but to extrinsic circumstances.

CHAPTER II.

Treatment of Acute Pleuritis-Measures indicated in the First Stage-General Considerations relating to Bloodletting in Acute Inflammations-The use of Opium in Acute Pleuritis and other Acute Inflammations-Measures indicated in the Second and the Third Stage of Acute Pleuritis.

THE objects of treatment in acute pleuritis differ in its different stages, and the latter, therefore, claim, severally, distinct consideration with reference to therapeutic indications. The objects in the first stage are to arrest, if possible, the progress of the disease, to diminish its intensity, if it be not arrested, to limit the amount of morbid products, and to relieve suffering; in other words, the treatment relates to the employment of abortive, curative, and palliative measures. The indications in the first stage of this disease are essentially the same as in the early period of most acute inflammations. The general principles which should govern the treatment in this stage, therefore, will be here considered, and simply referred to hereafter in connection with other diseases to which they are measurably applicable.

Owing to its brief duration, patients are frequently not seen until this stage has passed. Can the disease be arrested at this stage if the opportunity offer and a positive diagnosis be made? This question must be answered in the negative. There are no known reliable means of rendering the disease abortive. Bloodletting, opium, or any other measures which have been employed for this object, have certainly not been successful in a sufficient number of cases to warrant their employment to an extent which will render them likely to do harm if they are not successful. The disease must be expected to go on to the second stage; and, assuming this, the question then is, what curative and palliative measures are to be employed? This question leads at once to the consideration of bloodletting.

A great change has taken place, within the last few years, with respect to bloodletting in the treatment of acute inflammations. This measure was formerly thought to be highly important, and was rarely omitted. It is now considered by many as seldom, if ever, called for. The infrequent use of the lancet now, contrasted with its frequent use twenty-five years ago, constitutes one of the most striking of the changes in the practice of medicine which have occurred during this period. It can hardly be doubted that this mea

sure was formerly adopted too indiscriminately, and often employed too largely; but, with the natural tendency to pass from one extreme to another, it may be that the utility of bloodletting in certain cases, at the present time, is not sufficiently appreciated.

Experience and pathological reasoning combine to show that bloodletting does not exert a direct controlling effect upon an inflammatory disease. It may exert a powerful immediate effect as a palliative measure, and whatever curative power it may possess is exerted indirectly. Its therapeutic action. consists in lessening the frequency and force of the heart's action; in other words, in diminishing the intensity of symptomatic fever. In the early. period of an acute inflammation accompanied by high febrile movement, as indicated by a pulse accelerated and of abnormal strength, the abstraction of blood affords relief, and may contribute to a favorable progress of the disease. It should enter into the treatment of a certain proportion of cases, provided other and more conservative means for the same ends are not available.

The evils of bloodletting arise from its spoliative effect upon the blood. It diminishes the red corpuscles, and these, during the progress of an acute disease, are not readily reproduced. It induces, thus, the anæmic condition, and in this way impairs the vital powers. It will be likely to do harm, therefore, whenever it is important to economize the powers of life, and it may contribute to a fatal result in diseases, or cases of disease, which involve danger of death by asthenia.

The useful effects of bloodletting may frequently, if not generally, be obtained by other means which require less circumspection in their employment, because, if injudiciously resorted to, they are in a less degree hurtful. The mass of blood may be temporarily lessened by saline purgatives and diaphoretic remedies, conjoined with a restricted ingestion of food and liquids. Depletion is obtained in this way without spoliation or impoverishment of the blood. The frequency and force of the heart's action may be affected by nauseant sedatives such as tartar-emetic, ipecacuanha, etc., and by direct sedatives, viz., digitalis, aconite, and the veratrum viride. By saline depletories and sedatives, the symptomatic fever may be modified without the expenditure of blood, and thus the evils of bloodletting avoided. The advantage of bloodJetting consists mainly in the promptness of its operation. Several hours are required to secure results from the means employed in lieu of bloodletting, while the effects of the latter are produced in a few moments.

In accordance with these views, bloodletting is never indicated by the fact simply that acute inflammation exists; it is a measure directed, not to the disease per se, but to circumstances associated with the disease. The state of the circulation, and other circumstances, furnish the indications for the employment of this measure. It is admissible if, with the development of inflammation, there exist high symptomatic fever, the pulse denoting augmented power of the heart's action; the patient robust and in good health when attacked, and the disease not involving danger of death by asthenia. The measure is admissible under the conditions just stated, whenever the promptness with which its effects are obtained renders it desirable to adopt it in preference to other measures producing the same effects with some delay. Per contra, bloodletting is not admissible when the development of inflammation is not accompanied by high symptomatic fever, and the pulse does not indicate augmented power of the heart's action; nor when the patient was not in good health when attacked, nor when the constitution is feeble, nor when the disease involves danger of death by asthenia. These rules of practice, while they accord to bloodletting therapeutic value, undoubtedly restrict its use within narrow limits.

Applying these rules to the disease under consideration, a patient in the first stage of acute pleuritis, robust, perhaps plethoric, suffering from severe pain and a sense of oppression, with a strong non-compressible pulse, will derive immediate relief from the abstraction of from ten to sixteen ounces of blood. The loss of this quantity of blood under such circumstances, in a disease like this which does not tend to destroy life by asthenia, will give rise to no evil results, but will be likely to affect favorably the progress of the disease. On the other hand, a patient feeble or perhaps anæmic, with a pulse denoting excited action, not increased power, should not be bled, notwithstanding the local symptoms would undoubtedly be thereby relieved. By impairing the vital powers, the loss of blood will do harm, and is not admissible, under these circumstances, merely as a palliative remedy. And, in the first case, if the local symptoms do not urgently call for immediate relief, other measures may be substituted for the bloodletting.

Before leaving the consideration of bloodletting, several incidental points may be briefly noticed.

This measure is perhaps more applicable to the treatment of inflammation affecting the pulmonary organs than to the treatment of other inflammatory affections, in consequence of the relations of the former to the circulation. The free passage of the blood through the pulmonary circuit seems to be promoted, and the functional labor which the lungs have to perform is diminished by the abstraction of blood. At all events, relief of the sense of oppression and dyspnoea attendant on the early stage of acute inflammation of any of the pulmonary structures is more quickly and effectually procured by bloodletting than by other measures. Were it not for its ulterior effects, it would be invaluable as a palliative measure in pleurisy and other inflammatory affections within the chest.

The evils of indiscriminate and excessive bloodletting are manifested by a larger rate of mortality in those diseases which tend to destroy life by asthenia, and it can hardly be doubted that the death-rate has been diminished by a much more sparing use of the lancet within late years. But the results of injudicions bloodletting are manifested in cases which end in recovery, as well as in those which end fatally. These results consist in a protracted convalescence and subsequent feebleness. The cases of different inflammations treated formerly by bloodletting and other measures entering into the so-called antiphlogistic method, and the cases now treated otherwise, present a striking contrast as regards the condition of patients during convalescence and after recovery.

The opinion is held by some that diseases, and the human constitution, have undergone a notable change during the last quarter of a century, and that bloodletting and other antiphlogistic measures are less appropriate now than formerly, on this account. This opinion seems to me not well founded. After a professional experience extending beyond the period just named, I do not hesitate to express a conviction that acute inflammations at the present day are essentially the same as they were twenty-five years ago, and that antiphlogistic measures were no more appropriate then than now.

Were it true that such changes have occurred, the fact would strike at the root of medical experience. If changes requiring a revolution in therapeutics are liable to occur with each successive generation, it is evident there can be no such thing as permanent principles of practice in medicine; the fruits of experience in our day, which so many are striving to develop, will be of no utility to those who are to come after us.

In addition to general bloodletting, or the employment of venesection, much importance was formerly attached to the abstraction of blood by cups