Volume 3 — DISEASES OF THE RESPIRATORY SYSTEM. (continued 13)

Sometimes a latent pneumonia with typhoid symptoms is mistaken for typhus fever: especially is this the case when the latter is prevailing. I frequently saw cases where such a mistake had been made while in charge of the typhus-fever patients on Blackwell's Island during a typhus epidemic. In these cases there will be active typhoid symptoms, such as dry tongue, delirium, high temperature, etc. The countenance in this pneumonia, although the cheeks may have a purplish hue, does not exhibit that dull, heavy leaden expression so commonly seen in typhus fever. Although there may be delirium in both instances, the delirium in the former disease is of a milder type than in the latter. The characteristic pneumonic expectoration is often absent in this class of cases; therefore it cannot be relied upon as a point in the differential diagnosis. If pulmonary consolidation is a complication of typhus fever, it will not be developed until after the sixth day of the fever, the time when the eruption is visible. If no eruption is present, the pneumonic consolidation may be regarded as the primary affection, and the symptoms which simulated those of typhus fever may be regarded as secondary.

Pneumonia with typhoid symptoms is sometimes mistaken for typhoid fever. It is called typhoid pneumonia. The differential diagnosis is not difficult if one remembers that the pneumonia which complicates typhoid fever does not come on until late in the fever, and the regular history of typhoid fever precedes its development. On the other hand, when the typhoid symptoms are present from the beginning or come on at the end of the second stage of pneumonia, the physical signs of pneumonia will attend or precede the typhoid symptoms. If a patient over sixty years of age with this type of pneumonia is not seen until the second or third week of his sickness, although evidences of lung-consolidation may be found, it will be very difficult to decide whether the pneumonia is or is not complicating a typhoid fever; and under such circumstances a differential diagnosis may be impossible.

PROGNOSIS.—The mortality-rate of pneumonia is shown by the following statistics: Of 12,421 cases treated in the hospitals at Stockholm, 11 per cent. died. In the Vienna hospitals 24 per cent. died. The Basle hospital's report for thirty-two years gives 23 per cent. of deaths, Grisolle reports 59 per cent. of deaths in those over sixty years of age. In the United States medical reports from May 1, 1861, to July, 1866, of 61,202 cases which occurred among the white troops, 14,738 died, or a little more than 24 per cent.; and of 16,133 among the colored troops (for the same period) 5233 died, or nearly 33 per cent. The deaths from all other inflammatory diseases of the respiratory organs for the same period were only one-seventh as many as from pneumonia. The Confederate hospital reports give the rate of mortality from pneumonia for twenty-five months of the same period as 33¹/3 per cent. Of 255 cases treated in my wards in Bellevue Hospital during a period of four years, the rate of mortality was 34 per cent.

The statistics given of private practice differ remarkably from those of hospital reports, and are somewhat contradictory. Of Lebert's 205 cases, 7³/10 per cent. died. Ziemssen lost only 3¹/3 per cent. of his cases. Bennett (mentioning, however, that no complication existed) lost none of his 105 cases. Brundes of Copenhagen lost more than 21 per cent. of his 142 cases. Wilson Fox gives to pneumonia the fifth, and Walsh the third, place among fatal diseases. The mortality-average from all the published reports to which I have had access gives 20.1 per cent. of deaths.

From such facts it must be admitted that a disease in which death occurs in 1 out of every 5 cases should be classed among the very fatal diseases. But the death-rate varies very much at different times: it is to-day the same as when Andral wrote, nearly fifty years ago. He stated that it varied from 33 to 2 per cent. There can be no doubt but that treatment somewhat influences the variations in the mortality-statistics, but not to such an extent as to account for the great differences in the reports of different observers.

The prognosis depends more upon the age of the patient than upon any other single element. In infancy the mortality is greater than in early childhood, in which period statistics give from 4 to 6 per cent. as the ratio. The period of dentition seems to influence the prognosis in children. Between the ages of forty and sixty the death-rate is from 10 to 25 per cent.; uncomplicated cases will recover. After sixty the prognosis is exceedingly grave, and the greater the age of the patient the less are the chances of recovery.

Statistics do not give pneumonia its proper place among the fatal diseases of old age. My own experience leads me to believe that it is the most fatal of all acute diseases at this period of life, for the large number of autopsies in which it has been found to be the cause of sudden death in individuals of advanced years, and the frequency with which red or gray hepatization is found at the autopsy when pulmonary disease was not suspected during life, must greatly increase the statistical rate of mortality. Many modern authorities, who have had large experience in the hospital practice of the aged, state that nearly nine-tenths of those who die over sixty-five die of pneumonia. Pneumonia is more fatal in females than in males, in the proportion of about 3 to 2.

Statistics vary in regard to the influence of seasons on the prognosis in pneumonia. In some years the proportion of deaths is far greater in summer than in either the spring or winter. And it must be acknowledged that certain as yet unknown atmospheric influences are of the utmost importance in determining the death-rate in different years. Statistics do not show that the mortality-rate is greatest during cold weather.

The prognosis is greatly influenced by the extent of the pneumonia. Double pneumonia is not often recovered from, and pneumonia of an entire lung is more dangerous than when only a single lobe is involved. In pneumonia at the apex in infancy and old age the prognosis is unfavorable. The more feeble the patient at the time of the attack, the less are his chances of recovery. Previous attacks have no influence over the prognosis.

Most authors make mention of certain diseases that complicate pneumonia. Few give condensed statements of their influence on the death-rate. In 255 cases of my own, 87 were fatal and 168 recovered. Of these 255 cases, 124 were complicated and 131 were uncomplicated. Of the complicated cases, 75 died; of the uncomplicated, 12. Of these complications, alcoholism was present in 30 cases, pleurisy in 17, Bright's disease in 13, pericarditis in 9, hypertrophy and dilatation of the heart in 3, peritonitis in 2, fibrinous bronchitis in 1, and rubeola in 1. Lebert in his statistical report on pneumonia states that he lost only 5½ per cent. of his uncomplicated cases and all of his complicated cases. Huss of Stockholm lost 6 per cent. of his uncomplicated and 20 per cent. of his complicated cases. Wilson Fox says that, according to the reports of English physicians, pneumonia complicated by endocarditis is fatal in 75 per cent. of the cases; complicated by pericarditis, in 54 per cent.; by Bright's disease, in 50 per cent.; and by alcoholism, in 25 per cent. Brundes of Copenhagen in 120 uncomplicated cases lost only 6²/3 per cent., while of 22 complicated cases he lost all, or 100 per cent. Thus it is evident from my own records, as well as from those of others which I have given, that the rate of mortality in complicated pneumonia is much greater than in uncomplicated.

By a careful study of these complications it is apparent that they all exert a direct influence upon the heart, diminishing its power and crippling its action by obstructing the blood-current from the right ventricle toward the lungs. It is unnecessary to discuss these complications in detail; it is sufficient to state that weakening of the contractile power of the cardiac muscle is an essential feature of endocarditis, pericarditis, Bright's disease, and alcoholismus. In all acute infectious diseases such complications are regarded as dangerous, because they increase the liability of heart-failure when such failure is especially to be feared.

Other complications in addition to those already mentioned which increase the mortality-rate in pneumonia are chlorosis, phthisis, emphysema, laryngitis, oedema glottidis, bronchitis, pleurisy, parotitis, pregnancy, erysipelas, and rheumatism. Bronchitis, pleuritis, and jaundice do not seem to increase the mortality-rate very much, although they certainly influence it; while pregnancy, parotitis, and affections of the joints are very serious complications. Excepting small-pox and cholera, abortion is more apt to occur during the course of pneumonia than in any other acute disease.

A case of pneumonia may be called mild so long as the temperature does not rise above 104° F.; an elevation of temperature above 106° F. for two days renders the prognosis unfavorable. Wunderlich⁴⁸ says that a gradual rise in temperature after the fourth day is always an unfavorable symptom. A low temperature is dangerous only when the respirations are very much accelerated.

⁴⁸ In Die Eigenwärme in Krankheiten.

When the pulse is 120 or 130 for two or three days, the prognosis is bad; if the pulse reach 150 per minute, a pneumonia patient rarely recovers. An irregular and intermittent pulse, and one whose tracing exhibits dicrotism, has a most unfavorable prognosis. In children the rapidity of the pulse is not of so much importance, while in old age the pulse is seldom or never a reliable element in prognosis. A feeble, irregular, and intermitted pulse is always an unfavorable symptom.

Prune-juice expectoration is also an unfavorable sign, as it indicates extensive blood-changes or a depraved condition of the patient. If there is an entire absence of expectoration in the second or third stage of a pneumonia, or if it becomes scanty and difficult, the prognosis is unfavorable. Any sudden suppression of the expectoration, with coincident tracheal râles, in any period of the disease, indicates impending death.

In adults delirium is an unfavorable symptom, except when it occurs at the onset of the pneumonia. When delirium occurs late in one who is the subject of chronic alcoholismus, it generally indicates a fatal termination. Convulsions in children with great jactitation, and in old age subsultus tendinum and a tendency to coma, are unfavorable signs. Great exhaustion and signs of prostration, accompanied by a sunken, pallid countenance and cold, clammy perspiration, are always attended with danger. In children bronchial breathing after the seventh day, numerous subcrepitant râles, copious and persistent diarrhoea, and swelling of the veins of the hands, are unfavorable.

In old age a sudden rise or fall in temperature, apathy, somnolence, and a sallow countenance, are all symptoms indicative of great danger. Any complication renders the prognosis unfavorable, and the occurrence of pulmonary oedema or congestion in the unaffected parts of the lung is to be regarded as a forerunner of death.

Purulent infiltration, the formation of an abscess, and the development of gangrene are all attended with danger. Recovery from gangrene is very rare.

Death does not result from heart-clot, for the conditions which favor the forming of the clot precede its formation. The fibrin factors in pneumonia are increased—often 400 per cent. more than normal. The heart is so enfeebled that the right ventricle cannot empty itself; the columnæ carneæ and the chordæ tendineæ whip up the residual blood (already prepared for clotting). Heart-clot, it is well known, is the rule when the death struggle is prolonged and the cardiac contractions gradually become weaker and weaker. Such heart-failure is always the beginning of death.

In seeking for the causes of death in pneumonia, observers have taken the results of their post-mortems as a standard of their observations. One finds oedema of the lungs at the majority of his autopsies, another finds a clot in the heart in most of his fatal cases; hence the conclusion is reached that pulmonary oedema and heart-clot are causes of death in pneumonia. But it must be remembered that in every disease there is a great difference between the cause and the mode of death. If, as a result of the failure of heart-power during the last hours of life, pulmonary congestion and oedema are developed and clots are found in the heart-cavities, it ought not to be assumed that these conditions are the cause of death. Jürgensen states that in fatal cases of pneumonia oedema of the lungs is always present, and heart-clots are frequently met with.

Death may occur, then, from heart-insufficiency, from some of the complicating diseases (cardiac especially), or from asphyxia. In some cases death seems to come from the overwhelming of the system with a poison which acts primarily and principally upon the nervous system. In a few cases fatal collapse has followed an apparently regular, well-marked crisis.

TREATMENT.—The treatment of croupous pneumonia involves not only many unsettled questions in modern therapeutics, but it embraces a history of the therapeutics of inflammation. An heroic, antiphlogistic plan of one period gave place to the rational plan of another, and that in turn to the expectant plan of a later period, while to-day an antiseptic method finds many advocates.

Regarding it as a general disease with characteristic local lesions, and not a local inflammation with constitutional symptoms, its treatment must vary with the constitutional condition of the patient and the type of the disease. When uncomplicated and occurring at certain periods and in certain conditions of life, it will terminate spontaneously in recovery. But when certain complications exist and certain conditions are present, and at certain ages, it is almost necessarily fatal. Any plan of treatment in such a disease, if resorted to indiscriminately, must needs be unreliable and unsatisfactory.

Although there is no doubt that a large percentage of cases of croupous pneumonia will recover without treatment, there is also little doubt but that well-directed therapeutical efforts can save lives and render convalescence less tedious. If it is remembered in the treatment of pneumonia that the pneumonic lung no more requires treatment than do the intestinal ulcers in typhoid fever, and that we are to be governed by the patient's general condition, and not by the physical changes in the lung as indicated by the physical signs, it is evident that all those measures which have been employed for the arrest of a local inflammatory process have no place in our therapeutics. It is for this reason that venesection, which at one time had its stronghold in the treatment of pneumonia, has now fallen into disuse. A summary of the arguments against its practice seems to be conclusive, and the numerous discussions that have so often distracted the most careful and truthful observers are well expressed in the following terms:⁴⁹ 1st. That indiscriminate bleeding immensely increases the mortality of the disease. 2d. That it is specially fatal in old people and in young children, in patients of exhausted constitutions, and in those suffering from chronic diseases, and particularly from Bright's disease. 3d. That it is absolutely unnecessary in the majority of cases of young adults and also young children. 4th. That in the majority of cases it has no influence whatever either in cutting short the disease, in lessening its duration, or in diminishing the pyrexia, but that occasionally these results appear to follow from its use when practised early. 5th. That in the majority of cases it hinders the critical fall of temperature and delays convalescence. 6th. That in the majority of cases, as shown especially by Bennett's and Didel's data, recovery is equally if not more rapid when it is not practised as when it is resorted to. 7th. That in a few cases a moderate venesection may be necessary in the early stages to avert immediate danger of death from asphyxia.

⁴⁹ Wilson Fox, Reynolds's System of Medicine.

Not only does indiscriminate bleeding increase the death-rate and have no influence over the progress, course, or severity of pneumonia, but it postpones crisis and convalescence, and in the old, young, and enfeebled is very often nothing less than a fatal procedure. In a robust, vigorous individual, in spite of the fact that a free bleeding at the very onset will temporarily relieve the urgency of some symptoms, it nevertheless diminishes by so much the chances of recovery, lessens the power to fight against the disease, and makes the patient far more pregnable to subsequent dangers and complications.

Venesection has no influence upon the temperature. It may sometimes postpone imminent death from asphyxia; and the fact that there is one condition in which bleeding may be practised is no contradiction to the foregoing statements, for venesection is then resorted to on account of conditions that must be treated independently of the coexistent pneumonia, such as sudden engorgement of the heart with blood, attended with all the signs of sudden and extensive pulmonary oedema and congestion. When the patient is vigorous and the above-mentioned emergencies exist, free bleeding gives prompt relief. In no case should more than ten ounces of blood be taken.

A careful study of the pathology of pneumonia not only leads one to the conviction that venesection must do harm, but it strongly contraindicates the employment of all those remedial agents which have been used to arrest a simple pulmonary inflammation. Hence tartar emetic, veratrum viride, aconite, and all other cardiac sedatives which at one time were used so extensively have now fallen almost entirely into disuse, as by their effects they can only add to the burden of a heart already overtaxed by the venous stasis and the lack of arterial blood. They may for a time lower the temperature and diminish the pulse-rate, but they will accomplish this at the expense of heart-power, and will almost certainly favor the earlier and more certain development of that heart-insufficiency which must be regarded as the most powerful death-producing agent in pneumonia. Dangerous collapse has frequently followed the free use of these drugs.

Veratria is claimed to be a cardiac depressant; and this fact should make us hesitate before we administer it in pneumonia. It acts promptly in slowing the pulse, but its effects are only temporary, and when used for a couple of days the larger doses that are necessary to bring about the desired results interfere with the nutrition of the patient, often causing vomiting and diarrhoea. Aconite is also a cardiac sedative, but my experience with it has convinced me that it is in all respects inferior to veratria. Digitalis, which may be regarded as a cardiac stimulant, is to be preferred to either veratria or aconite. It not only lowers the temperature, but lessens the frequency of the pulse, steadies it, and produces in the majority of cases its well-known tonic action upon the heart. Its use in children is sometimes followed by an intermittent pulse, but it is a symptom of no dangerous import.

Calomel and antimony have been almost entirely discarded from the therapeutics of pneumonia: there is no evidence that the former has any influence either upon the progress of the disease or the absorption of the pneumonic exudation. Those who advocated its use believed it to be most advantageous after the patient had been freely bled and large doses of tartar emetic had been given. The latter was also a part of the treatment where bleeding was practised. It exercises a depressant effect upon the heart, and hence, although it may diminish the frequency of the pulse and lower the temperature temporarily, it is an exceedingly dangerous relief, as it is obtained at the expense of vital power. It is absurd, with our present knowledge of the pneumonic process, to discuss what was once claimed for tartar emetic—namely, that it had the power of arresting the pneumonic process as well as preventing pulmonary congestion in the unaffected portion of lung. These drugs, while they at best afford only temporary relief, require most careful watching to guard against their dangerous and prostrating effects.

Expectorants have no place in the treatment of pneumonia, as only a very small portion of the exudative matter in the lung is removed by expectoration. If mucus or other secretions accumulate in the bronchial tubes in sufficient quantities to cause inconvenience, it is in consequence of the exhaustion and a loss of muscular power which attend the disease, for which expectorants will afford no relief.

Counter-irritation, by blisters or other irritants applied to the surface of the chest in the earlier stages of pneumonia, is of questionable utility. Occasionally, blisters may be applied during the third stage to hasten the process of resolution and promote the absorption of plastic exudation. The application of leeches, followed by a linseed poultice or some other soothing fomentation, will often relieve the pain in the side which is so urgent at the onset of a pneumonia. If extensive pulmonary oedema occurs, dry cups applied to the chest will afford relief to the dyspnoea and temporarily remove the oedema.

It has come to be a quite universal practice in this city to encase the chest in a layer of cotton batting or flannel covered with an oil-silk jacket. While this procedure has no direct influence on the course of the pneumonia, it promotes diaphoresis and protects the surface from sudden changes of temperature, and is always grateful to the patient. It is especially serviceable in children.

A pneumonic patient should be kept in bed, as nearly as possible in a horizontal position. Every appliance for promoting rest should be employed. He should be cautiously moved for the necessary examinations of the chest, and should be kept as short a time as possible in a constrained position. If there are evidences of heart-failure, the sitting posture should be avoided and talking should be prohibited. The sick-room should be large, cheerful, and well ventilated, and its temperature should range between 65° and 70° F. In acute febrile disease there is no danger of catching cold from draughts, and the idea of the laity that the moment a person is sick or has a fever he must be put in a dark, close room is one of the superstitions of ignorance. Pneumonic patients always demand air, and the cooler the more grateful it is. Pure fresh air has a marked antipyretic power. It is a good rule to allow adults to regulate the temperature of the sick-room to suit their feelings.

One of the most important things in the successful treatment of pneumonia is a carefully-regulated diet. The food should be fluid or semi-fluid and highly nutritious, such as milk, eggs, beef-tea, and concentrated meat-broths. Milk is to be preferred to all other forms of nutrition. It should be given in small quantities at short intervals.

When not contraindicated wine may always be administered with milk. Such administration of wine is not a part of the stimulating plan of treatment hereafter to be considered, but it is a means of increasing the digestive power of a feeble stomach.

If expectoration becomes difficult, it may be from a loss of muscular power in the bronchial tubes, when stimulants are indicated; or from extreme viscidity of the sputa, when alkalies will be of service. Just here it may be mentioned that alkalies and neutral salines possess a diuretic and diaphoretic power which often affords relief from the pungently hot skin, and may aid the elimination of effete material by the kidneys.

It should be remembered that in the treatment of croupous pneumonia we have to do with a self-limited, acute febrile disease, which usually runs a cyclical course.⁵⁰ Routine treatment is therefore always harmful.

⁵⁰ Fernet ("De la Pneumo. franche aigue," etc. Arch. gén. de Méd., 1881, pp. 5–155) has demonstrated the regular and cyclical course of pneumonia. The evolution of the malady is represented by the march of the fever and is figured by the thermometric curve.

The nervous shock which attends the ushering in of a severe croupous pneumonia is greater than in any other acute disease, unless it may be peritonitis, and the important question presents itself at its very onset, What measures shall be employed to overcome or mitigate the impression made upon the nerve-centres by the morbific agent which is operating to produce the pneumonia? The experience of the last few years leads me to the conclusion that during the developing period of the disease, when the pneumonic blow is first struck, and until the pneumonic infiltration is completed (usually for the first four days of the disease), if the patient is brought under the full influence of opium, and held in a condition of comparative comfort by hypodermic injections of morphia repeated at regular intervals, he is placed in the best condition not only for resisting the shock, but also for combating the activity of the pneumonia. Opium does not, when thus administered, interfere with a stimulating or antipyretic plan of treatment which may be demanded, but it does very greatly diminish the chances of heart-failure, cases often recovering under its use which from age and condition of life seemed hopeless. Then the great relief and comfort which it gives to the sufferer in the first four days of his struggles are sufficient to commend it, especially in those cases where pain is severe and the restlessness of the patient is exhausting.

After the pneumonic infiltration is completed opium should be administered with great caution, for paralysis of the bronchi (which it induces), and the consequent accumulation of secretion in the bronchial tubes, may greatly increase the already existing difficulty of respiration.

In all severe types of croupous pneumonia there are two prominent sources of danger: heart-insufficiency and high temperature. There are consequently two prominent indications for treatment—viz. to sustain the heart and reduce temperature.

A large proportion of deaths from pneumonia result directly or indirectly from heart-failure. Alcoholic stimulants, judiciously employed, are the most efficient means which we possess for sustaining a flagging heart, but their indiscriminate use is more dangerous than indiscriminate venesection. It may be that only a few ounces of brandy will be required to carry a pneumonia patient through a critical period, or it may be that its free administration will be required to save life. In the old and feeble, and in those who have been accustomed to the use of alcohol, stimulants may be indicated from the commencement of the attack, and their free use required throughout the whole course of the disease. Each case demands careful study. In no other disease is so much discretion and judgment required in the administration of stimulants as in croupous pneumonia. The pulse, being the indicator of the condition of the heart, must be carefully studied. A frequent, feeble, irregular, or intermittent pulse always indicates heart-insufficiency. The quantity of stimulants to be administered in any case must be determined by their effect upon the pulse. It is advisable to commence their use in small quantities, and carefully watch their effects. If the effect is beneficial, a favorable result will follow within a few hours, and then the quantity to be administered can be increased according to the necessities of each case. It is seldom necessary to give more than six or eight ounces of brandy in twenty-four hours, yet if the necessity of the case demands it may be given in much larger quantity, twelve or twenty-four ounces often being required in twenty-four hours. A dicrotic pulse is a certain indication for the administration of stimulants.

The period immediately following the crisis is the one in which stimulants are usually most serviceable. Delirium is a symptom which calls for their administration, whether it is due to asthenia, pyrexia, or is an expression of blood-poisoning. When muscular tremor and subsultus tendinum are present, alcohol may usually be freely given. A critical collapse in the aged and weak, attended by great prostration and a subnormal temperature, is a condition in which alcohol shows its best effects, and the amount of asthenia will determine the amount of stimulation required.

It has been claimed that carbonate of ammonium in large doses stimulates the heart and prevents the formation of heart-clots by its action on the blood. The cause of heart-clot is the heart-failure, and there is no evidence that carbonate of ammonium prevents the coagulation of the blood when the blood-current is slowed. Besides, large doses of carbonate of ammonium irritate the stomach, and on this account interfere with nutrition, and thus diminish the chances of recovery. As a diffusible stimulant it is inferior to champagne. Moreover, champagne can be administered for a much longer period without causing gastric disturbances.

Camphor and musk have been highly recommended as cardiac stimulants, but they are inferior to alcohol.

Digitalis of late years has been extensively used to counteract heart-insufficiency, but it is very uncertain in its action in the heart-insufficiency of pneumonia, and has seemed to me more frequently to do harm than good. The nervous element of the heart-failure contraindicates its use.

The second important indication in the treatment of croupous pneumonia is to lower the temperature. The plan of applying cold compresses to the chest in pneumonia, though far from being a new one, still has its strongest advocates in the modern school of therapeutics. It is proposed to apply thick compresses wet in ice-water over the seat of the inflammation, changed every five minutes. Some use the Esmarch ice-bag for the same purpose. Patients who were moribund have, it is said, been revived by immersion in a cold bath. The advocates of this treatment claim that the temperature is lowered; that the patient experiences a feeling of relief during the bath; that the pain, dyspnoea, pulse-rate, restlessness, and severity of the attack are all ameliorated; and that the duration of the disease has been cut short by the continued use of cold baths or cold packs.⁵¹

⁵¹ Rules for the employment of cold as an antipyretic in pneumonia:

Cold Bath.—As soon as the axillary temperature in the evening rises above 103° F., place the patient at full length in a bath with a temperature of 70° F. or 80° F. Gradually lower the temperature of the bath by the addition of cold water or ice until the temperature of the patient begins to fall. It may be necessary to lower the temperature of the bath to 60° F. before the temperature of the patient is affected. After the temperature begins to fall, thermometrical observations must be taken every two or three minutes; the rectal temperature only can be relied upon. If the temperature falls rapidly—that is, two or three degrees in five or six minutes—as soon as the fall reaches 102° F. the patient should be removed from the bath; if it falls slowly, as soon as it reaches 101° F. he should be removed and immediately placed in bed. The patient should never be kept in the bath until the temperature reaches the normal, for it continues to fall for some time after his removal from the bath, and he may pass from a condition of fever into a state of collapse. The duration of the bath should rarely exceed fifteen minutes. While the patient is in the bath cold should be applied to the head by means of a sponge or by an ice-bag.

In the young, the feeble, and the aged the duration of the bath should never exceed five minutes. Once commenced, the baths must be persisted in until the crisis is reached.

Cold Pack.—This is much less effective than the bath, but if the patient is too feeble to be moved it may be employed. The patient should be wrapped in a sheet wrung out of tepid water, and over this a sheet should be applied wrung out of ice-cold water; the latter may be removed as often as it becomes warm. Its application and removal may be continued until the desired fall in temperature shall be obtained.

Cold Compresses.—The method of applying cold compresses in pneumonia is as follows: A cloth of some thickness is to be wrung from ice-cold water and applied every five minutes to the affected side, or an ice-bag is employed instead of the compresses. It is claimed for this method that it not only relieves the local symptoms, but lowers the temperature and hastens the day of crisis.

If cold is to be applied to the chest, either moist or dry, all the disadvantages arising from repeated exposure and frequent changes of temperature can be avoided by the use of the rubber coil, and it should always be employed in preference to wet compresses.

The experience of American practitioners, so far as I have learned, is against this plan of treatment. It is found that under it pneumonia is more liable to extend; that the shock of the cold to the surface causes a nervous depression from which the old and feeble do not rally; that although a reduction of temperature may be effected, heart-insufficiency is more rapidly reached and is more difficult to overcome. Besides, the statistical results of this plan of treatment are decidedly against its use. The above statements do not prohibit cold sponging of the limbs and face if it is grateful to the patient.

If the high temperature in pneumonia is due to rapid tissue-metamorphosis, the result of the action of some morbific agent in the blood, it follows that we must look for an antipyretic which can check this rapid tissue-change. It is claimed with reason that the sulphate of quinia is a sedative to the arterial system, and has a stimulating effect, sui generis, upon the capillary circulation; that it can arrest cell-development, and also check the amoeboid movements of the white corpuscles. Theoretically, therefore, it is a remedy par excellence for the lowering of the temperature in this disease; and clinically and empirically it has been found to reduce temperature more permanently and with greater certainty than any other agent. None of the objections brought against the other antipyretics can be urged against this one, for it possesses the twofold power of reducing temperature and sustaining the heart-power from its action on the nervous system. To act antipyretically, quinia must be given in large doses. From twenty to forty grains must be given within two hours, or the whole quantity may be given at a single dose. The greatest reduction of temperature will be reached in about seven hours after the quinia is taken.⁵²

⁵² When quinia is employed as an antipyretic in pneumonia it must be given in large doses. The administration of two grains every two hours, or a larger quantity administered in divided doses within a period of twenty-four hours, will not act as an antipyretic; but from twenty to forty grains must be administered within a period of two hours. If the stomach is irritable, ten grains may be given every half hour until the desired quantity has been administered. Usually in from four to six hours after the antipyretic dose has been taken the fall of temperature will begin, and in about twelve hours it will reach its minimum height; then it will remain stationary from twelve to twenty-four hours. After the temperature has once been reduced by the quinia, its administration may be discontinued until the temperature shall again rise to 105°. As a rule, the temperature does not reach as high a point as before the quinia was administered. This mode of administering quinia rarely produces any symptom of cinchonism other than transient deafness after the first dose. In a large proportion of cases the temperature by this method can readily be kept below 103° F.

In Ringer and Gill's experiments with quinia on temperature it took at least twenty grains to produce a fall of a degree. From fifty to eighty minutes were required before the fall occurred, and the effects lasted from forty-five minutes to three hours. Ringer states that in pneumonia the quinia does not readily pass out with the urine, but is delayed in the system for a considerable time.

Lately, antipyrine has been brought before the profession as a valuable and powerful antipyretic. I have used it in both private and hospital practice, and have found it a prompt and efficient means of reducing temperature. It has not seemed to me, however, to have any other beneficial effect either in mitigating the severity or shortening the course of the disease. In two cases its use was followed by collapse, which in one case terminated fatally. My experience has seemed to bear out the belief that this drug is a decided cardiac depressant, and I should for this reason consider it much less desirable as an antipyretic than quinia.

During convalescence tonics and restoratives—iron, quinia, the mineral acids, cod-liver oil, or strychnia—should be administered, and the highest degree of nutrition should be maintained. If bronchitis complicates pneumonia, it may be treated with muriate of ammonium, ipecacuanha, and senega. If severe gastric catarrh occurs, hot fomentations may be applied to the abdomen, and calomel, followed by a saline purgative, may be administered.

Diarrhoea is rarely so severe as to require treatment; five grains of Dover's powder usually suffices to control it.

In the delirium which occurs in alcoholic patients small doses of the tartrate of antimony and potassium are said to be useful. I have controlled this form of delirium best with small doses of hydrate of chloral.

By some, camphor, musk, and turpentine are recommended during the stage of gray hepatization, but it seems to me that the requirements are far better fulfilled by alcoholic stimulants.

In the first stage of senile pneumonia an emetic, when not specially contraindicated, is given in the Salpétrière Hospital. The physicians of the Montpellier General Hospital regard ipecacuanha as an heroic remedy in senile pneumonia. The English regard nitrate of potassium as the most efficacious, while the Germans prefer hydrochlorate of ammonium. Antipyretics are rarely necessary in senile pneumonia; the most important thing is to sustain the heart by stimulants and concentrated fluid nutriment combined with iron and quinia. In senile pneumonia the diarrhoea occurring with the typhoid form must be promptly checked by vegetable astringents.

In children, as in old age, leeches and blisters should never be used. The whole chest should be enveloped in a linseed-meal poultice, to which some anodyne may be added (opium, aconite, or belladonna) if there is severe pain.

In asthenic pneumonia, in addition to the nutritious diet, burgundy, port wine, or brandy should be used, and stimulant embrocations should be applied to the chest. In children the state of the bowels must be most carefully watched. Stimulating expectorants are more frequently necessary than at any other period of life.

In conclusion, I would urge that all remedial measures which tend to paralyze the heart should be excluded from the treatment of pneumonia, and great care should be exercised not to over-stimulate the heart, for over-stimulation often results in paralysis. It must always be remembered that in the milder cases there is necessity for no treatment except a regulated diet and attention to those general hygienic measures which have already been referred to.

I shall not attempt to discuss the treatment of the complications which may occur in the course of a pneumonia, for it is impossible to even mention every contingency that may arise. The rule is to treat the pneumonia so long as it is the controlling disease, and the complication when it shall have become the most prominent and dangerous element in any given case. In prolonged convalescence it is of the utmost advantage that the pneumonic patient shall have a change of scene and climate.

Antiseptics.—The use of antiseptics in the treatment of pneumonia has as yet given no definite results. I have employed hypodermically phenic acid after Declat's method in several well-marked cases of simple pneumonia, without being able to determine that the temperature or course of the disease was at all influenced by its use.

F. Schwarz⁵³ states that the very favorable results which he has obtained in croupous pneumonia can only be due to one thing—i.e. the specific action of iodine, which renders inert the exciting cause of the disease, which he regards as an organism, and that its efficacy is limited exclusively to the very early stage of the pneumonia. He believes that its action in acute lobar pneumonia is the same as Von Willebrandt claimed for it in typhus, typhoid, and in malarial fevers. He even states that he regards iodine as a genuine specific in pure uncomplicated croupous pneumonia if employed within twenty-four or thirty-six hours after the ushering-in chill, that hinders its development and arrests its progress.

⁵³ Deutsche medicinische Wochenschrift, January, 1881, No. 2.

After using benzoate of soda in diphtheria, scarlet and puerperal fever—drachm ij in the twenty-four hours—E. B. Cady⁵⁴ states that when an epidemic of pneumonia visited his town in Wisconsin he had equally good results from the similar use of this salt in pneumonia, cases recovering which had a temperature of 106° F. and 107° F.

⁵⁴ N.Y. Med. Record, 1880, July, 3, "Benzoate of Soda in Pneumonia."

Orth⁵⁵ has recently written an interesting account of the treatment of pneumonia (lobar) with iodine.

⁵⁵ Allg. med. Centr. Zeitschr., Berlin, 1881, i. p. 181.

T. H. Buckler strongly recommends its treatment with salicylate of sodium and fresh lemon-juice.⁵⁶

⁵⁶ Phila. Med. News, 1882, xl. p. 652.

Phenic acid, boracic acid, and the salicylates are highly recommended by many as the best drugs in the antiseptic treatment.

CATARRHAL PNEUMONIA.

BY WILLIAM PEPPER, M.D., LL.D.

SYNONYMS.—Broncho-pneumonia; Lobular pneumonia. Although numerous other names have been used to designate this affection, it is undesirable to perpetuate them.

DEFINITION.—Catarrhal pneumonia is an inflammation of the parenchyma of the lungs, frequently bilateral, and affecting scattered groups of lobules, which may, however, coalesce, so that considerable areas of lung-tissue become continuously involved. This anatomical distribution explains the name lobular as opposed to that of the lobar or croupous form. As implied by its other titles, it has close associations with bronchial catarrh, and occurs nearly always either as an extension of inflammation from the larger tubes or in connection with capillary bronchitis. In consequence, it is often combined with pulmonary collapse, with which latter condition it was until recently confounded. The affected areas show lesions of the bronchioles, together with a morbid product filling the alveoli, and consisting in varying proportion of altered epithelial cells from the alveolar walls, of cells drawn by aspiration from the bronchioles, and of exudation from the blood-vessels. Catarrhal pneumonia may be circumscribed or diffuse, and acute, subacute, or chronic. Its course and duration vary greatly: at times it terminates fatally in a few days, or runs a lingering chronic course, while recovery rarely occurs in less than fourteen days. The mortality is always considerable, and it acquires additional gravity from its tendency to leave behind it organic lesions of the lungs or even to induce phthisis.

ETIOLOGY.—As catarrhal pneumonia is so closely associated with bronchitis, and so commonly preceded by it, it may be premised that all the causes of bronchial catarrh must be considered as liable to induce this form of pulmonary inflammation, whether they do so by exciting bronchitis, which subsequently extends to the alveoli, or whether, as more rarely happens, they affect simultaneously the lining membrane of the bronchi and of the lobules.

There are, however, several influences which must here be carefully considered, since they have a special tendency to determine the production of the more grave form of disease.

The effect of age in predisposing to catarrhal pneumonia is undoubtedly great, and yet it seems to have been often over-estimated, since by many this has been regarded almost as a disease peculiar to childhood. The great frequency with which young children were formerly held to be affected by this form of pneumonia has, however, been found to be due in part to the fact that many cases of pulmonary collapse were included with it; while, on the other hand, there is strong reason to believe that the frequency with which adults are attacked has been greatly under-estimated in consequence of the failure on the part of the profession at large to clearly recognize this affection. It seems in the highest degree important that more correct views on this subject should be generally received. While it is probable that the more severe and widely-disseminated pneumonias of catarrhal type are commonly recognized now-a-days, it appears undoubted that in very many instances of apparently mild sickness, of acute or subacute character, which are regarded as simple febrile colds or as the result of malaria, the true condition is one of circumscribed catarrhal pneumonia, which, while threatening no immediate danger to life, may if neglected leave lesions of grave significance. Still, it is undoubted that it is during the early years of childhood, and particularly the first five years, that catarrhal pneumonia, and more especially its grave and fatal form, is of frequent occurrence; while the period of next greatest liability is at the other extreme of life, among aged and debilitated subjects.

Under the head of Pathology we shall have occasion to dwell on the relations between defective respiratory power, pulmonary collapse, and catarrhal pneumonia; and it is evident that this connection helps to explain the relative frequency of the latter in early childhood, when conditions of debility are so common, and when rickets not rarely is superadded as an important factor. Another potent cause of the liability of young children to catarrhal pneumonia is the prevalence at that period of life of the infectious diseases, which are apt to be complicated with bronchitis, and which then present a combination of conditions favoring its development. This is especially true of measles, of whooping cough, and of diphtheria, while influenza, which is also frequently complicated with this form of pneumonia, is operative at all ages. Among predisposing causes which operate chiefly at a later period of life must be mentioned organic diseases of the heart and vesicular emphysema. The latter especially has shown itself important in our experience, both as predisposing to the occurrence of catarrhal pneumonia and as adding to the gravity of the attack.

Unquestionably, all states of bad nutrition and depressed vitality render the system much more liable to attacks of catarrhal pneumonia. The bad air of crowded houses or of ill-ventilated public institutions, especially if conjoined with the effect of improper food and of other defects of hygiene, plays an important part in inducing the fatal forms of this disease which are common among children exposed to such conditions. It is equally evident that among adults the effect of overwork, with insufficient sleep and outdoor exercise, is to develop a peculiar sensitiveness and weakness of system which make the ordinary causes of bronchitis capable of exciting a deeper and more serious catarrh. Finally, there are many individuals who possess a catarrhal diathesis—that is, in whom the epithelial layers are especially vulnerable, and when attacked are especially prone to take on cellular proliferation of a deep-seated and obstinate character. Such constitutions, which are frequently found in the subjects of phthisical heredity, furnish a ready soil for the development of catarrhal pneumonia.

Nor must the practical lesson be here overlooked that when acute or subacute bronchitis exists, an additional motive for prompt and thorough treatment is to be found in the fact that undue fatigue or exposure may be followed by an extension of the inflammation and by the onset of catarrhal pneumonia.

PATHOLOGY AND MORBID ANATOMY.—Allusion has already been made to the relation existing between catarrhal pneumonia and collapse of the lung; and the present seems to be the proper place to speak more fully of it, since in order to appreciate the lesions in any case it is necessary to distinguish between those which are the result of the inflammatory process and those which can be explained by simple collapse of the lung-tissue. It is indeed true that in some cases the development of catarrhal pneumonia takes place in areas already the seat of collapse. This is only what would naturally be expected. For the production of both conditions the existence of preceding bronchial catarrh is, if not necessary, at least highly favorable. The folds of the swollen mucous membrane of the smaller tubes come into contact with each other, or else the diminished lumen of the tubes is occluded by the viscid mucus formed as the result of the catarrh. The normal activity and rhythm of respiration is disturbed by the fever and the lowered innervation. During expiration more and more of the air escapes from the alveoli of the affected area through these partly-obstructed tubes, while during inspiration, owing to the less force of that part of the respiratory act and to the shape of the bronchial tree, air cannot enter to replace it. Thus, or by the action of a plug of mucus in a conical bronchial tube, serving as a ball-valve, a condition of airlessness or of collapse is induced in a more or less extensive area. It is not, indeed, to be supposed that the mere occurrence of such collapse serves in any way to excite inflammation of the alveoli. But at the same time it is evident that there will be a strong likelihood that the catarrh which has advanced so deeply into the finer tubes will extend in some spots to the alveoli, and consequently that in a collapsed area of some extent there will be one or more foci of pneumonia developed. Moreover, it must be remembered that the collapsed lung-tissue becomes more or less hyperæmic and disposed to take on inflammatory action, and that the irritating bronchial secretions, the suction of which into the alveoli plays an important part in these affections, would necessarily be less apt to be dislodged by cough and expectoration from areas which had become collapsed. On the other hand, it is evident that when areas of catarrhal pneumonia have occurred directly from extension or establishment of catarrh in air-containing alveoli, the conditions will exist which favor the development of collapse in the surrounding zones of lung-tissue. Thus it happens that while the lesions either of collapse or of catarrhal pneumonia are found separately, it is common to find more or less evidences of alveolar inflammation in connection with collapse, especially if it has lasted any length of time; and still more common to find a considerable proportion of collapse coexisting with catarrhal pneumonia.

A simple practical rule must therefore be here insisted upon: that in all post-mortem examinations of the lungs in cases of catarrhal pneumonia, after careful study of the external appearances, a moderate inflation by means of a blowpipe must be practised, and the effects of this upon the consolidated areas be carefully studied before the lung be incised, in order that any element of collapse may be recognized and eliminated.

The external appearance of the lungs usually presents evident lesions. There are patches or layers of soft lymph on the pleura over the affected areas, and when the former are removed the serous membrane is found roughened, congested, and ecchymosed. On the other hand, while the pleura over a collapsed patch usually presents small ecchymoses, there is rarely any evidence of inflammation. More or less evident signs of vesicular emphysema are also usually present, bearing some proportion to the extent of the pulmonary collapse. When the areas affected are small and scattered, the emphysema is limited to their neighborhood; but when, for instance, both lower lobes are extremely involved, the upper lobes may present a high degree of emphysematous distension. In rare instances subpleural emphysema, from separation of the membrane over a pneumonic focus, may be observed; and even, as in a case published by me some years ago,¹ perforation of the separated pleura may occur, leading to pneumothorax.

¹ Philada. Med. Times, Aug. 15, 1872, p. 425.

After section of the lungs there will always be found lesions of the bronchial mucous membrane, which presents evidences of catarrh extending as high as the trachea or larynx in some cases, but habitually growing more intense in the finer tubes, where the membrane is reddened and swollen. Frequently the infiltration extends throughout the structure of the bronchial walls, so that the tubes stand out prominently above the surface of the section. Delafield² has insisted with especial emphasis upon these alterations in the bronchial walls, and on the view that the inflammation extends from the bronchi, not to the group of air-vesicles into which they lead, but directly outward to the peribronchial zones of lung-tissue. In severe cases of longer standing the bronchial tubes often present in addition dilatations, either cylindrical or more rarely globular.

² "The Pathology of Broncho-pneumonia," Medical News, Nov. 15, 1884, p. 534.

The bronchi contain morbid secretions in the form of clear viscid mucus in the early stage, while later they are filled with creamy pus. In some cases there are also found small subpleural collections of more or less inspissated yellowish secretion contained in dilated alveoli or in small globular dilatations of terminal bronchioles. The most plausible explanation of their nature is, as suggested by Fauvel, that they are caused by the suction of particles of bronchial secretion into the alveoli in the forcible inspiratory effects which follow paroxysms of cough, and especially such paroxysms as occur when whooping cough is complicated with catarrhal pneumonia.

The lung-tissue itself exhibits, associated in varying degrees, congestion, oedema, emphysema, collapse, and pneumonic consolidation. The patches of simple collapse are to be easily recognized by their familiar appearance, being depressed below the surrounding tissue, bluish in color, non-crepitant and solid to the touch, and on section smooth, airless, firm, and not friable. They sink in water. As already stated, they can, when recent, be readily inflated, and thus restored to their normal condition. Such patches are most common at the postero-inferior parts of the lungs. They are mostly pyramidal in shape, and vary in size from a few lines to one or two inches in diameter, though in severe cases an entire lobe, or even an entire lung, may pass into this state of collapse. On the other hand, the areas of pneumonic consolidation appear as slightly prominent nodules, varying in size from that of a pea to that of a hazelnut, which may be distinctly felt with the finger, if occurring in the midst of a collapsed patch, by their elevation above the surrounding depressed tissue. They are usually scattered throughout both lungs, often with some symmetry of disposition, especially in the postero-inferior portions. The surrounding zone of tissue is more or less congested and oedematous, and when the nodules are closely adjacent they may become confluent, so that large portions of a lobe or an entire lobe may become infiltrated. Vigorous inflation will usually show in such cases, however, that the consolidation is not uniform or complete. Section of the lung will show that the most varied stages of the inflammatory process are represented in the different nodules; and this is a highly characteristic feature of the disease. The recent nodules are brownish-red or grayish-red, faintly granular, smooth, friable, and yield on scraping a small quantity of thick reddish secretion. Later they become reddish-gray and yellowish-gray in color, yield a thick, airless, milky substance, and finally grow more firm and dry: the inflammatory product undergoes fatty degeneration, is gradually removed by absorption or by expectoration, and the affected area of lung-tissue is slowly restored to its normal state. This is the course in favorable cases, while in those which run into a chronic form or which terminate fatally at an early period the lesions undergo various modifications. In some instances the inflammatory product undergoes more acute degeneration, with destruction of the pulmonary tissue in the affected area, and the subsequent formation of abscesses, which are not to be confounded with the minute aspiration-abscesses above described. I have notes of autopsies in which the lungs have presented every stage of the process of catarrhal pneumonia, from the nodules of incomplete consolidation to circumscribed abscesses. In other cases the thickening of the walls of the alveoli and of the bronchi, together with dilatation of the tubes, has become marked, and the interstitial changes in the zones of peribronchitic pneumonia extend and induce a slow process of fibroid thickening which results in that form of chronic pneumonia which has been called cirrhosis of the lung and fibroid phthisis. In still other cases the morbid products in the alveoli, with or without an antecedent process of suppuration, undergo caseation; and the presence of the degenerate cheesy foci, associated with alveolar and peribronchial thickening, may lead to catarrhal phthisis with or without true tuberculous formations.

The microscopic examination of the pneumonic nodules shows that the essential condition consists in a morbid accumulation within the alveoli, together with changes in the walls of the vesicles, which become infiltrated with cells in the same way as the bronchial walls. These changes become more marked after the disease has lasted some time. The epithelium lining the alveolar walls is the seat of cloudy swelling, becomes less closely attached, and undergoes proliferation, with the formation of large epithelial elements. The morbid product filling the alveoli is composed in varying proportions of these latter elements, of the richly cellular bronchial secretion which has been sucked in from the bronchioles, of leucocytes, and much more rarely of red blood-corpuscles which have escaped from the pulmonary capillaries, and finally of fibrillated exudation. In contrasting these minute appearances of catarrhal pneumonia with those of the croupous form it is to be noted that in the former the fibrinous element is not constant, or is at most scanty, and that the results of diapedesis, leucocytes, and especially red corpuscles, are much less prominent. At a later period of the process fatty infiltration and degeneration of the alveolar contents usually occur, which is the most favorable change, since it disposes toward evacuation with restitution of the lung to its normal state; but at times a larger proportion of pyoid cells appears, and the alveolar walls become involved and break down, so that small abscesses are formed, or, again, the contents may become inspissated and caseous, associated with nuclear growth in the walls of alveoli and bronchioles.

An account has thus been given of the lesions in fully-developed and disseminated catarrhal pneumonia; but I would again ask attention to the existence of a mild and circumscribed form of the disease, which rarely if ever causes death of itself. In these mild attacks, which occur frequently in adults, the part affected may be the base of the lung, but more commonly it is the root, the apex, or the lower anterior portion of the upper lobe. The anatomical condition is probably one of congestion, with extension of catarrhal inflammation into the alveoli without any preceding collapse, and with a varying degree of implication of the walls of the vesicles and of epithelial accumulation in the alveoli, though the process may not always go on to the production of fully-formed pneumonic nodules, such as above described. Yet it seems to me not only illogical, but eminently unsafe, to regard such cases otherwise than as catarrhal pneumonia, since while under proper treatment and in fairly healthy constitutions they uniformly terminate in resolution, on the other hand, they will, if neglected or if occurring in highly-vulnerable constitutions, run into a subacute form, with more extensive implication of the alveolar walls and peribronchial tissue, and will induce catarrhal phthisis. Allusion will be made again to these cases when speaking of the symptoms and diagnosis of catarrhal pneumonia.

In addition to the pulmonary lesions, the bronchial glands are, with rare exceptions, swollen and congested. In cases of longer standing foci of suppuration have been occasionally noted in them (Steiner), though cheesy nodules are more common. Acute miliary tuberculosis is a comparatively frequent complication. Oedema and congestion of the brain and meninges occur frequently, but are to be regarded as secondary lesions without special significance. It is probable, however, that more numerous examinations, in cases where death has been preceded by grave cerebral symptoms, would reveal the occasional occurrence of circumscribed areas of meningitis, with or without miliary tubercles. The liver is congested in acute cases, while in older ones there is apt to be fatty degeneration, which we have seen occur in irregularly distributed patches, imparting a peculiar mottled appearance to the organ. The kidneys also may be congested, but serious changes in the epithelium are rarely met with. Vastly more common are the lesions of catarrhal inflammation of the mucous membrane of the stomach and intestine. While in acute cases they may be superficial and slight, in those which have run a longer course Peyer's patches are prominent, and the solitary glands are enlarged, and not rarely oval ulcerations exist which may coalesce, so that I have seen quite extensive destruction of the mucous membrane of the colon simulating the effects of dysentery.

SYMPTOMS.—Before entering on a detailed description of the symptoms of catarrhal pneumonia it must be premised that this disease presents a far greater range in its degrees of severity than does croupous pneumonia. In this latter disease, although clinical evidence shows that its extent and course are less uniform than is often assumed, there is a remarkable uniformity in the stages through which the inflammatory exudation passes; but in catarrhal pneumonia, as in all forms of catarrhal disease, it is a marked characteristic that the process varies almost infinitely in different cases, both in the location, the extent, and the degree of development of the lesions. It is difficult to avoid the conclusion that a corresponding variety is presented by the symptoms, and that a complete clinical picture of catarrhal pneumonia must include cases of very mild character and of short duration, as well as those of a more severe and fully-developed type. I propose, therefore, to describe a mild form, an acute form of the ordinary well-developed disease, and also a subacute and chronic form.

The mild form is undoubtedly often overlooked, the attack being regarded merely as a feverish cold or as an ordinary bronchitis. Yet certain peculiarities in the symptoms, the course, and the tendencies of the cases I refer to serve to distinguish them, and enable them to be recognized as of more serious nature. More commonly the attacks occur in young adults whose systems are abnormally sensitive either from original weakness or in consequence of overwork, previous sickness, or the action of other depressing and exhausting causes. After some imprudent exposure there is a slight rigor, followed by headache, flushed, feverish feeling, soreness in the chest, aching in the limbs, and tight, dry, painful cough. A careful examination soon after the onset would reveal the familiar signs of a bronchial catarrh, though even now there might be noted a tendency for the affection to be less diffused than is usual in ordinary bronchitis.

If the patient is not prudent and solicitous about his health, no physician is summoned at once, and not rarely in the course of forty-eight or seventy-two hours the general symptoms have subsided so considerably that the patient feels able to move about, and may be led by pressure of business claims to resume his occupation. He finds himself so weak, however, and the cough is so much aggravated, that medical advice is sought. Distinct fever of remittent type is found, the morning temperature not exceeding 100° or 100½°, while in the evening it rises to 102° or 103°. There is a tendency to perspiration, especially on exertion, while exposure to a cool wind or draught causes a chilly feeling; exertion soon fatigues; sleep is restless; appetite is impaired; the tongue coated; the bowels irregular; and the urine high-colored. Cough is troublesome and somewhat painful, and the chest feels sore and weak. Physical examination will reveal, in the first place, bronchitic râles, dry and moist (sonorous, sibilant, and mucous), on both sides of the chest, though not rarely much more markedly on one side than on the other, or even limited to a portion of one side.

In addition to this, careful auscultation, especially if conducted not only during ordinary respiration, but during the strong inspirations which follow cough, will detect in certain localities subcrepitant râles, associated with feeble respiratory murmur and slightly prolonged and blowing expiration. The percussion resonance or the vocal fremitus or resonance may be only slightly impaired. These signs, which are connected with an extension of catarrhal inflammation into the alveoli and the consequent partial occlusion of certain lobules, may be met with in the subclavicular spaces, at the lower anterior margin of the upper lobes, at the roots of the lungs, or elsewhere. If the patient be confined to bed and suitable treatment be employed, the local and general symptoms will pass away in five to ten days. The cough grows looser, and the sputa, which were at first very scanty and mucoid, grow muco-purulent, and then diminish in amount. There follows a greater degree of anæmia and of weakness than would have been expected from what is apparently so slight an ailment, and especially there remains a marked sensitiveness of the throat and chest, so that after any slight recurrence of catarrh there may be a temporary return of râles at the affected spot, until gradually the general health and the healthy tone of the lungs are restored. But if, on the other hand, the patient persists in keeping about and exposing himself, the febrile process of remittent type will be prolonged, and though the disturbance of general health will gradually subside, repeated renewals of catarrhal irritation will occur, and the local disease will become more deeply seated, will be attended with increased infiltration of the lobules, and if the reaction of the system be greatly depressed will end by becoming chronic. According to my observation, it is in this way—and this fact confers its great importance upon the mild circumscribed form of catarrhal pneumonia now under discussion—that very many cases of pulmonary phthisis begin; and according to the power of resistance of the tissues, and to the tendency of the system to become infected by the products of unhealthy inflammation will be the disposition for the disease to assume this unfavorable development. It is true that the precise anatomical conditions present in the early stages of such cases cannot be demonstrated, since death rarely if ever occurs at that period; but it seems difficult to regard them as differing from those found in partially developed patches of consolidation in more severe and typical cases of catarrhal pneumonia. The constitutional symptoms, the local signs, and the course and results of the affection all indicate that it is not an ordinary bronchial catarrh, but that it is properly to be regarded as a mild type of catarrhal pneumonia. Without pretending to describe minutely all the clinical features of these interesting cases, it may suffice to have called attention to their frequent occurrence and great actual importance, and to the fact that owing to the indifference of the patient or to the hasty examination of the physician their true nature is often overlooked and the disease is allowed to pass far beyond its original character of a local catarrhal trouble.

Acute catarrhal pneumonia in its fully-developed form occurs most commonly in children, especially as a complication of measles or in the course of capillary bronchitis. It is evident, therefore, that the passage from the stage of severe bronchial catarrh to that of alveolar inflammation may be barely perceptible at first. This is especially true because in such cases the development of the pneumonia is usually preceded by a considerable amount of pulmonary collapse. The child is already suffering with fever, rapid shallow breathing accompanied with movements of the nostrils and possibly with inspiratory retraction of the thorax, and with frequent painful cough. No rigor, as a rule, occurs to mark the inception of the pneumonic complication. The fever, however, nearly always rises rapidly, and from 102° or 103°, which has been the maximum during the preceding catarrh, it quickly reaches 104° or 105°, or even higher. It will be promptly noticed also that the respirations become even more accelerated, shallow, and imperfect; in some cases they reach 100 in the minute. The alæ nasi play violently; the elevation movement of the thorax is marked, while expansion is but slight; there is retraction of the base of the chest during inspiration, which is short and quick, while expiration is prolonged and labored. Severe suffocative paroxysms occur from time to time. The cough is frequent and painful, so that adults complain severely of it, while in children it causes moaning or crying. Later, when the nervous symptoms grow more prominent, the cough grows much less frequent and severe, or even ceases. Sputa are rarely raised by children unless with the act of vomiting; they are tenacious, but not rusty colored, though they may be slightly streaked with blood. The pulse soon grows very rapid, 160, 180, or even 200 in young children, and loses force and volume. The appetite is lost, but thirst is extreme. The tongue becomes brown and parched from deficient secretion and from mouth-breathing. Diarrhoea is not uncommon, owing to the frequent presence of intestinal catarrh as a complication. The urine occasionally contains a small amount of albumen; and it is stated (Bednär) that the chlorides persist. The nervous symptoms are prominent. As the dyspnoea increases there is extreme restlessness, the child tossing about incessantly, with slight delirium. Soon the flush on the face yields to a distinct cyanotic appearance, with coolness of the extremities. The restlessness subsides, and there is a tendency to stupor, alternating with spells of active and restless delirium, and finally deepening into coma, at times with rolling of the head, so that there may be a close resemblance to the later stage of tuberculous meningitis.

During the development of these symptoms the physical signs are for the most part unsatisfactory and require great care to determine and to interpret them. As already intimated, inspection shows inspiratory retraction of the base of the chest, increased movement of elevation, with defective expansion. Percussion does not usually give definite results, owing to the fact that the lesions may be symmetrical in the two lungs, and because the pneumonic process is complicated to a very variable extent with the results of pulmonary collapse. In children especially the most gentle and careful percussion is requisite to detect and map out the affected areas. Some assistance may be rendered by the fact that the dulness dependent on collapse is often found in the form of symmetrical elongated areas in either intervertebral groove. The results of palpation are even less satisfactory than those of percussion. If the patches of consolidation are not extensive and are scattered, no change will be detected; and it is only when superficial areas of considerable extent are consolidated that distinct increase of vocal fremitus can be determined. It may be remarked here that, on the contrary, there is impairment of fremitus over areas of pulmonary collapse.

Auscultation usually shows the continuance of the râles due to the preceding bronchitis. In addition to these coarser dry and moist râles there is also heard fine moist crackling over the area of pulmonary consolidation; these fine subcrepitant râles are heard both during inspiration and expiration. Pure bronchial breathing, such as is heard in croupous pneumonia, is by no means constantly present. Over large areas of catarrhal pneumonia, when the small bronchial tubes are comparatively unobstructed, it may exist; but, on the other hand, there may merely be weak diffused blowing breathing.

In adults an equally grave type of acute catarrhal pneumonia is not of such common occurrence. Cases are met with, however, occurring especially in subjects whose systems are depressed—as, for instance, by overwork—in old or feeble persons, or in connection with diphtheria, typhoid fever, or influenza. The disease may then run a course closely resembling that described above as found in children, the rapidly developing interference with aëration of the blood, the speedy failure of cardiac power, and the appearance of grave nervous symptoms all being strongly marked. Such cases constitute a notable proportion of what is commonly styled typhoid pneumonia, especially in the aged, the disease being often in reality catarrhal instead of croupous. I have also met with rapidly fatal catarrhal pneumonia developed during the course of typhoid fever, particularly during the later stages of cases marked by considerable bronchitis and great nervous depression. In one instance the patient, a young man of twenty-six years, who had been much exhausted by mental worry and anxiety, passed through a well-marked attack of typhoid fever with moderate pyrexia, but with decided nervous symptoms. Convalescence seemed established on the twenty-first day, when he was carelessly allowed to sit up in a chair, and while there was exposed to a draught of air; he felt chilly, fever reappeared with cough, but no rusty sputa; centres of catarrhal pneumonia developed in the lower lobe of the right lung, then in the middle lobe; the fever varied from 101½° or 102° in the mornings to 103½° or 104° in the evenings. On the seventh day there was a sudden fall to 99°, with a rise in the afternoon to 106°; centres of inflammation appeared in the left lung. For the next five days there were remarkable fluctuations of temperature, the range being from 100½° or 101° in the morning to 106° and 106½° in the evening. The variations in the pulse-rate were not so marked. Respiration was hurried and imperfect. Nervous symptoms of a typhoid and ataxic nature developed, and death occurred on the twelfth day. Considerable daily fluctuations in temperature, though rarely so regular and extreme as in this case, are often noted in catarrhal pneumonia, and are of some diagnostic importance. I have many tracings to show the remittent though atypical course of the pyrexia of this disease. Such grave cases of acute catarrhal pneumonia are very fatal, even in adults, scarcely less so indeed than in children; and when recovery occurs the convalescence is protracted, and often interrupted by more or less serious renewals of catarrhal inflammation with constitutional disturbance.

As already remarked, the pulse-rate, which soon becomes rapid, 110 to 124, does not vary as much as the temperature; and even during marked remissions of the pyrexia the pulse usually continues rapid. The appetite is greatly diminished or lost; the tongue is coated, often heavily so; vomiting is not often present spontaneously, but may be excited by the spasmodic attacks of cough. The respirations are hurried and superficial, frequently rising to 40, 50, or 60 in the minute in adults, and this rapidity persists during remissions of the fever just as does the rapidity of the pulse. As a rule, it is not possible to observe any marked difference in the movements of the two sides, owing to the irregular distribution of the foci of disease. The cough is frequent and may be painful. It is apt to occur in paroxysms, and the spells may be so severe as to cause alarming interference with respiration, and also to induce serious exhaustion.

The sputa are at first scanty and consist of tenacious mucus, which may possibly show fine blood-points, but which are quite different from the rusty-colored sputa of croupous pneumonia. Later the sputa become more abundant and less consistent, being much affected by the amount of bronchitis attendant.

The results of physical examination are much more satisfactory in adults than in children, owing partly to the less frequency of pulmonary collapse as a complication, and partly to the assistance obtained from the more careful study of the vocal fremitus and resonance possible in the former. Inspection will not show inspiratory retraction of the base of the chest to anything like the extent seen in children, owing to the greater rigidity of the thoracic walls. In the later stage of the disease, however, when considerable infiltration and obstruction of the lungs has developed, such retraction and also an inspiratory depression of the suprasternal space may be noted. Palpation does not give such clear results as in croupous pneumonia, yet careful observation will show relative increase of fremitus over the affected areas. Auscultation of the voice usually gives valuable results. They are not constant, however, nor is it common, even when a considerable area is consolidated, to meet with such bronchophony as in the second stage of croupous pneumonia. Still, it is nearly always possible to detect some alteration of the vocal resonance by comparing corresponding portions of the two sides; and this, as contrasted with the negative results in bronchitis, possesses high value. The respiratory murmur is usually feeble and blowing over the patches of catarrhal infiltration. In some cases it is as intensely bronchial as in the croupous form; but more commonly the greater or less obstruction of the bronchioles renders it weaker and more distant and diffused. I have observed considerable areas of consolidation due to catarrhal pneumonia, over which the respiratory murmur was so feeble as to suggest the presence of moderate pleuritic exudation. Râles are apt to be present at all stages of the disease. Usually they are fine subcrepitant or fine dry crackling râles, audible in both inspiration and expiration; and even over consolidated areas these may be audible, being doubtless transmitted from the fine bronchioles.

As the case progresses toward resolution the râles become larger and looser. It often happens that the râles are variable, changing in character, extent, and position from day to day vastly more than occurs in croupous pneumonia.

Percussion gives valuable data if practised with care over symmetrical areas of the two lungs. From such comparative study alone can satisfactory results be obtained, since in many cases the areas of disease are too small or not sufficiently superficial to yield more than relative dulness. But it must happen rarely that spots are not found where resonance is at least relatively impaired, while of course in some cases actual dulness is readily detected. It has been stated that collapse of the lung is a comparatively rare complication in adults, yet careful study of the physical signs from day to day will occasionally show its existence in a marked degree. It may occur in a striking manner in the subacute catarrhal pneumonia of emphysematous subjects; but in acute cases also considerable areas of the affected lung may quickly pass into a state of collapse. In a fatal case of the acute form in a young man I observed the abrupt development of the signs of pulmonary collapse over the whole lower lobe of the right lung, requiring care to avoid the error of supposing a considerable pleuritic exudation to have supervened, but passing away in the course of thirty-six hours with renewed expansion of the lobe and restoration of the previously existing physical signs.

It is not necessary to give any detailed discussion of the other symptoms of acute catarrhal pneumonia as occurring in adults—the atypical remittent type of fever; the rapid pulse and breathing; the digestive symptoms, anorexia, thirst, occasional nausea, and a comparatively frequent tendency to diarrhoea; the nervous restlessness and depression, with delirium supervening, at first slight, later more active, and toward the close of fatal cases of such violence as to require restraint, alternately with deepening stupor from exhaustion and defective aëration of the blood. Albuminuria may be present in a slight degree toward the close of severe cases. When death occurs in these acute cases it usually does so from the tenth to the sixteenth day. In children it may occur suddenly during or after a violent paroxysm of cough, or an attack of convulsions may be the immediate cause of death. More commonly death is preceded by evidences of increasing intensity of interference with the aëration of the blood, and with deepening stupor and nervous disturbances such as have been described. The degree of cardiac failure present is to be ascribed rather to nervous exhaustion than, as in many cases of croupous pneumonia, to the action of hyperpyrexia on the muscle of the heart. The extreme interference with respiration in catarrhal pneumonia is readily accounted for, not only by the extent of lung-tissue actually involved in the process, but by the associated bronchitis with swelling of the mucous membrane, by the accumulated bronchial secretions, and by the frequent complication with collapse. When recovery is to follow, the disease declines gradually and irregularly, slight recurrences of fever and renewed catarrhal irritation being observed from time to time. These exacerbations may not rarely be traced to atmospheric influences or to trifling indiscretions on the part of the patient. The pain declines gradually; and the pulse-rate also falls, but even after the temperature has become normal some degree of rapidity of the pulse is apt to remain for a considerable time. The physical signs gradually disappear: the respirations, like the pulse, remain somewhat rapid, or at least are for some time readily accelerated; and there is apt to be some cough remaining, with gradually decreasing muco-purulent expectoration. The digestive functions are also apt to be left in an enfeebled condition, and the recovery of full nutrition and health is often slow. A peculiar sensitiveness of the general system is frequently noted after this disease, so that morbid processes, especially of catarrhal type, are readily excited.

As would be expected, catarrhal pneumonia frequently presents much less violent symptoms and runs a much less acute course than above described, so that it may be said to assume a subacute or chronic form.

In children this may occur as the result of an acute attack, the severe symptoms gradually subsiding, and passing into a less violent but persistent type. In other cases the disease assumes this form from the beginning, and such instances are more commonly noted after ordinary bronchitis of moderate severity or after whooping cough. In adults this form also is less common than in children. It is met with as an intercurrent affection in certain cases of phthisis; and not rarely the exacerbations of that disease are due to the development of centres of catarrhal pneumonia which too often become later the seat of an extension of the tuberculous process. It occurs in this form also in the old and cachectic, and doubtless proves the undetected source of death in many cases where the end is preceded by irregular pains and by some signs of hypostatic infiltration of the lungs. In a feeble and exhausted state of the system at all ages it is liable to be induced. At times this is brought about by a series of recurring slight catarrhal attacks, gradually deepening into a subacute process of catarrhal pneumonia; while in other cases a more powerful disturbing cause will in such states of system directly induce this type of the disease. It develops insidiously. There is little or no pain. The fever is highly irregular; the maxima usually occur in the evening and reach 102° or 103°, but there may be such marked remissions as to make the case closely simulate one of intermittent malarial fever complicated with bronchitis, and I have known such an error to be made in repeated instances. In some cases, especially in the old and feeble, there may be very little fever, at least until the disease is more fully developed. The dyspnoea is not urgent; the pulse is not extremely rapid; and cough may actually seem diminished if the disease has originated in the course of severe bronchitis. The physical signs develop slowly, but may eventually appear over considerable areas of lung-tissue. In this way with an irregular fluctuating pyrexia, presenting from time to time marked exacerbations, with an equally varying amount of cough and muco-purulent expectoration, and with marked and progressive debility and emaciation, these forms of catarrhal pneumonia pursue a course extending over many weeks or months. Complete recovery is still possible, after a tedious convalescence. Commonly, however, some permanent lesion of the lungs, as emphysema, dilatation of the bronchial tubes, or circumscribed induration of the lung, will remain as sequels. In a large proportion of cases a fatal result finally follows, more commonly from the passage of the morbid process into pulmonary phthisis usually associated with true tuberculosis; while in some cases acute miliary tuberculosis supervenes and proves rapidly fatal. Undoubtedly, however, cases of chronic catarrhal pneumonia may continue purely as such, with recurring exacerbations at irregular intervals from the development of new centres of disease, until death is finally induced by exhaustion.

COMPLICATIONS AND SEQUELS.—It is needless to repeat what has been said as to the essential connection between catarrhal pneumonia and bronchitis, so that the latter is to be regarded as an invariable symptom and attendant rather than as a complication. As might be expected also, catarrhal laryngitis of varying degrees of severity is of comparatively common occurrence. Especially in cases occurring in connection with measles, where the upper respiratory tract is already inflamed, the increased intensity of the laryngitis may induce so much swelling as to cause some mechanical obstruction to respiration which will arouse fears of pseudo-membranous formation, and which, during the spasms of cough and dyspnoea which are apt to occur occasionally, will closely simulate true croup. Pleurisy rarely appears in such a high degree as to constitute a serious complication. When the areas affected are superficial, there is apt to be circumscribed plastic exudation on the corresponding portions of the pleura. Less frequently quite extensive plastic pleurisy occurs, with layers of exudation sufficiently thick to modify the physical signs; and in still more rare instances does fibro-serous effusion occur. I have noted the occurrence of purulent pleurisy, as has Jürgensen; and in two cases it was found to be associated with subpleural purulent foci, one at least of which had ruptured. In the other cases the purulent character of the pleurisy was presumably due to the constitutional dyscrasia. Allusion has already been made to the occurrence of emphysema and bronchiectasis in connection with catarrhal pneumonia, especially of the subacute and chronic varieties. The observations of Delafield on the tendency of the catarrhal inflammatory process to extend laterally through the bronchial wall into the peribronchial zones of lung-tissue are of special interest in their bearing on the liability to dilatation of the bronchial tubes and to deep-seated circumscribed indurations of lung-tissue as sequels of catarrhal pneumonia.

Gangrene of the lung I have known to occur as a complication in one case of extraordinary severity, but in which recovery ultimately followed a very tedious process of reparation. It was attended with recurring attacks of hæmoptysis. The case occurred in a young man of twenty-four years of age: the lesions existed chiefly over the right back, though there were smaller centres elsewhere; and the spot of gangrene and from which the hemorrhages occurred was near the right root. He was four months in bed; his convalescence extended over a year; evidences of induration at the above spot lasted five years; and now, eight years after the attack, he is in vigorous health, though still with slight cough.

Pneumothorax may occur as a sequel in protracted cases in consequence of the rupture of a subpleural abscess. I have elsewhere reported cases of this, and Steffen has also reported two instances.

Tuberculosis occurs in various ways in connection with catarrhal pneumonia. There may be a development of acute general miliary tuberculosis, owing to the depressing and irritating effect of the disease upon a constitution strongly predisposed to tuberculosis. Or tuberculous pulmonary phthisis may ensue, either directly as a complication or as a sequel to ulcerative changes of inflammatory nature in the lung. Finally, those who have passed through an attack of catarrhal pneumonia are usually left with such vulnerability of system that any predisposition to phthisis or to tuberculosis is very apt to be readily called into activity. It seems highly important to note this close and complicated connection between catarrhal pneumonia, in its various types and even in its mild and circumscribed form, and subsequent organic disease.

Further evidence of the profound disturbance of nutrition often effected by an attack of this disease may be found in the occasional development of marked rachitis, and in the much more frequent establishment of subsequent anæmia and debility, which prove obstinate and are associated with a high degree of susceptibility of the system to morbid influences, and which are doubtless, in some instances at least, dependent upon impaired primary assimilation due to lesions of the intestinal canal, which existed as complications of the original attack of catarrhal pneumonia. It has been mentioned that gastro-intestinal irritation is often present, both in the acute and in the more chronic forms, and this may reach such a high degree as to justify the name of a complication. It has seemed to be especially in these cases, or in those where, owing to the subsequent vulnerability of the system, gastro-intestinal catarrh occurs as a sequel, that the serious impairment of nutrition above mentioned is most likely to ensue.

Lastly, allusion must be made to the frequency with which severe nervous symptoms appear, especially during the later stage of the attack. As has been seen, convulsions are not rare in children, while at all ages active delirium and extreme restlessness, often requiring restraint, are of frequent occurrence. These cannot be attributed, as a rule, to uræmic intoxication, but are to be referred to the high systemic irritation, the great nervous exhaustion, and the marked interference with respiration and aëration of the blood. It is probable also that circumscribed areas of lepto-meningitis, or even of tuberculous meningitis, are of occasional occurrence in these cases.

DIAGNOSIS.—The direct recognition of catarrhal pneumonia in its acute stage is not always free from difficulty, while both in the acute and chronic forms there are certain conditions with which care must be used not to confound it.

In the first place, it is important to recognize at the earliest moment the development of the pneumonic process during acute bronchitis of the finer tubes. In all cases of the latter, especially in children and in patients of debilitated system, this occurrence must be constantly apprehended. Its occurrence may be strongly suspected if sudden rise in the fever and in the rate of respiration and pulse is noted, though if the areas affected are small, scattered, or deeply seated it may not at first be possible to demonstrate it. It must be remembered also that in the capillary bronchitis of children the fever and disturbance of pulse and respiration may be aggravated quite abruptly from extensions of the disease, so that actually it must be recognized that in such cases the presence of small pneumonic centres can only be assumed, but can neither be proved nor disproved. The course of the pyrexia may afford some assistance, since I believe more marked diurnal variations, amounting at times to distinct remissions, will be noted in cases of catarrhal pneumonia than in those of severe bronchitis not so complicated. In adults less hesitation need be felt in admitting the development of pneumonic foci under such circumstances, even though the physical signs are negative. Usually, however, carefully repeated examination will soon reveal the signs of infiltration in irregularly disposed areas; and I suspect it must be infrequent that the close study of the relative physical signs afforded by examination of the corresponding areas on the two sides of the chest will not afford substantial ground for diagnosis.

It must always be remembered that areas of consolidation arising in the course of severe bronchitis of the finer tubes may be from collapse, and not from pneumonia. This is especially apt to be the case in children, but occurs not rarely in feeble adults. The diagnosis of catarrhal pneumonia from mere collapse must therefore be carefully considered. The occurrence of collapse, though it may be marked by sudden and severe increase of dyspnoea, pulse-rate, and distress, is not accompanied by a corresponding rise of temperature; and this is a point of capital importance. Again, the development of the physical signs is usually much more abrupt than where catarrhal pneumonia is occurring. Considerable areas of dulness on percussion appear in the course of twelve or twenty-four hours, between the successive visits of the physician, without corresponding increase of fever; and these areas may subsequently present marked peculiarities, at times disappearing almost as abruptly, to be succeeded by similar areas in other portions of the lungs, though at times also they persist and pass through the changes already described. The physical signs furnish further assistance. Retraction of the base of the chest during inspiration is much more common in collapse, especially when the areas are at all extensive and when they occur in the lower lobes, since there is necessarily a reduction in the volume of the lungs; and this, added to the inability to inflate the affected lobules, induces this important sign, which should always be carefully looked for. The dulness over collapsed lung-tissue is rarely as marked as over extensive areas of catarrhal pneumonia; the vocal resonance and fremitus are diminished; râles are wanting or are feeble and transmitted; and again, it must be mentioned that the physical signs present remarkable variations within short periods of time. It is, however, necessary to suspect the existence of pneumonic areas in cases of severe bronchitis where portions of lung become collapsed, and continue so, while the general symptoms indicate persistence of inflammatory action. The differential diagnosis is therefore in many instances rather as to the relative proportion of these factors than as to the total absence of either.

Catarrhal may be confounded with croupous pneumonia. This error may most readily be made if the case be not seen until a consolidated area of considerable extent is present, since, as we have seen, in some instances the foci of catarrhal pneumonia may chiefly occupy one lung and may coalesce. Even then, however, the dulness of percussion rarely corresponds with the outline of the lobe, and is rarely as complete as in croupous pneumonia, nor are the bronchial respiration, the bronchophony, and the exaggerated vocal fremitus as pronounced, for the simple reason that the consolidation is not so uniform, and that many of the smaller bronchial tubes are more or less obstructed by swelling of the mucous membrane or by the accumulation of viscid secretions. It will rarely happen, moreover, that strong efforts at respiration—induced, if necessary, by having the patient cough during the auscultation, so as to ensure a full inspiration—will fail to develop subcrepitant râles at some point of the catarrhal consolidation. To this must be added the information drawn from the history of the case; the character of the cough and sputa; and, above all, the atypical course of the pyrexia, and the fact that carefully-repeated examinations will show frequent and abrupt variations in the physical signs around the margins of the affected area. If the case is observed during its development, there will be less difficulty in making a correct diagnosis. The process is very rarely unilateral throughout its development; and the evident bronchitis, the development of irregularly scattered foci of partial consolidation in both lungs, and the frequent coexistence of collapse, combined with the absence of the characteristic symptoms and course of the croupous form, make the nature of the case apparent.

The diagnosis of ordinary pleurisy with effusion from catarrhal pneumonia presents no difficulty. But, on the other hand, it is not easy to recognize the occurrence of a moderate pleuritic effusion complicating a catarrhal pneumonia. The fact that the lower lobes of both lungs are apt to be involved in the pneumonic process interferes with the displacement of the heart, and the enfeebling of the respiratory and vocal phenomena may be attributed to bronchial obstruction or to collapse. A careful study of the outline of the dull area, and of the effect upon it of changes in the position of the patient's body, has proved of service. After all, this is a rare complication; but not so rare is the coexistence of plastic pleurisy with catarrhal pneumonia, and this also may give rise to doubt in the diagnosis. An area of dulness appearing near the base and extending with moderate rapidity, attended with bronchial irritation, with irregular fever of slight or of moderate degree, and with some evidences of engorgement of the lower part of the opposite lung, and presenting over the affected area, in addition to marked percussion dulness, bronchial respiration not of intense concentrated type, distant bronchophony, no increase of vocal fremitus, and crackling râles irregularly scattered over the affected area, represent a clinical condition, occasionally met with in adults, which requires care to ensure its proper interpretation. I have observed crackling râles in particular in such cases, which might have been regarded either as intrapleural or as developed in the finest bronchioles. It will be observed, however, that the degree of dulness is excessive for a mere plastic pleurisy; that the respiratory and vocal signs, while not typical of croupous consolidation, are yet far more developed than would be consistent with the presence of a quantity of plastic pleural exudation sufficient to cause such dulness; that any such grade of plastic pleurisy is very rare; and that the general symptoms and the course of the disease are indicative of much more gravity than would attach to such a pleuritic process if it were to exist. It is altogether probable that there has been here a coexistence of catarrhal pneumonia with a moderate degree of plastic exudation on the corresponding part of the pleura.