rants a conjecture that the same measure may be extended equally to pericarditis with effusion.

In performing paracentesis of the pericardium, the method practised by Dr. Bowditch in cases of pleurisy is to be preferred. This method consists in the introduction of a small exploring trocar, to the canula of which is attached a suction-pump. The wound made by this instrument is trivial, the liquid may be withdrawn slowly, the quantity regulated by the immediate effects, and the operation repeated as often as may be deemed advisable. The trocar is to be introduced in the fourth or fifth intercostal space between the nipple and the sternum, the patient lying upon the back; the physical signs showing the pericardium to be in contact with the thoracic walls at the point of puncture, and the heart removed from the walls at that situation. M. Aran, of Paris, has reported a case in which a solution of iodine was injected, after the removal of the liquid, with apparent benefit.

PNEUMO-PERICARDIUM AND PNEUMO-PERICARDITIS.

Air or gas gains access within the pericardium by means of fistulous communications with the stomach, oesophagus, or the pulmonary organs; or through wounds of the chest perforating the pericardial sac; and in rare instances it is generated by the decomposition of liquid products within the sac. Inflammation, with more or less liquid effusion, is almost invariably present. The affection is then properly designated pneumo-pericarditis. It is analogous to that variety of pleuritis which is commonly known by the incorrect title-pneumo-hydrothorax. But inflammation is not necessarily present. In a case related to me by Dr. Knapp, of Louisville, to which reference has before been made, a patient was stabbed with a knife, which penetrated the pleural cavity and perforated slightly the pericardium. A splashing sound with the heart's action was immediately heard, which continued for a few days and disappeared. The symptoms and signs, subsequently, did not denote pericarditis, but the patient had pleurisy, which was followed by considerable contraction of the left side. The splashing sound, in this case, was fairly attributable to the presence of air and probably a little blood

within the pericardium. The recovery was complete, and the patient was examined by me some two or three years after the injury. In such a case, the affection, assuming that inflammation was not present, is properly called pneumo-pericardium.

Dr. Stokes relates a case in which the coexistence of liquid and gas was predicated on the peculiar auscultatory phenomena. The account is best given in his own words. "The patient was a young man of lymphatic temperament, who had labored under an attack of acute pericarditis for a few days before I saw him. On my first examination he presented the usual signs of dry pericarditis, with a considerable effusion of lymph of the ordinary consistence. The rubbing sounds, though loud and distinct, had nothing unusual in their character, and the patient suffered but little distress. After two or three days I saw him again, and found that his state had become very much altered. His appearance was haggard and worn, and he complained of extreme exhaustion, which he attributed to a total deprivation of sleep. This was induced by the extraordinary loudness and singular character of the sounds proceeding from the cardiac region; for though up to this period the rubbing sounds were distinctly perceptible by means of the stethoscope, the patient was quite unconscious of their existence. They had suddenly, however, become so loud and singular, that the patient and his wife, who occupied the same apartment, were unable to obtain a moment's repose. On examination, a series of sounds was observable which I had never before met with. It is difficult or impossible to convey in words any idea of the extraordinary phenomena then presented. They were not the rasping sounds of indurated lymph, nor the leather creak of Collin, nor those proceeding from pericarditic with valvular murmur, but a mixture of the various attrition. murmurs with a large crepitating and a gurgling sound, while to all these phenomena was added a distinct metallic character. In the whole of my experience I never met with so extraordinary a combination of sounds. The stomach was not distended with air, and the lung and pleura were unaffected, but the region of the heart gave a tympanitic bruit de pot felé on percussion; and I could form no conclusion but that the pericardium contained air in addition to an effusion of serum and coagulable lymph. In the course of about three days the signs of air disappeared, leaving the phe nomena as they were at the first period of the case. The convalescence of this patient was slow, and the rubbing sounds continued

for an unusual length of time. His recovery was ultimately perfect.""

Dr. Stokes, in connection with this case, cites two additional cases, one reported by Dr. Graves, and the other communicated by Dr. B. McDowel. In Dr. Graves' case, pericarditis was induced by the opening of a hepatic abscess into the pericardial sac. The case proved fatal, and after death it was ascertained that the abscess also communicated, through a fistulous opening, with the stomach. The gas contained within the pericardium was derived from the stomach passing through the hepatic abscess. The patient presented over the præcordia friction-sounds, with an occasional metallic click, giving the idea of a fluid dropping in the pericardium. Afterwards the sounds assumed the character of an emphysematous crackling. In Dr. McDowel's case, a fistula was found, after death, to have become established between the pericardial sac and a small anfractuous cavity in the right lung. A current of air through the trachea was observed to rise through the fluid contained in the pericardial sac, and the latter, when opened, contained air. Over the left side of the chest, in this case, auscultation discovered metallic tinkling, and splashing of fluid caused by the action of the heart.

In a case reported by Dr. Walshe, in which a communication existed between the oesophagus and pericardium, produced by the effort to swallow a knife, tympanitic resonance on percussion over the præcordia was marked, but neither a splashing noise nor metallic tinkling were observed. A distinctive phenomenon in this case "consisted in the change of position of tympanitic and dull percussion-sound, within the area of the cardiac region, according as the posture of the patient was changed from one to the other side."

These cases are of much interest as showing the physical signs distinctive of the presence of air or gas and liquid within the pericardium. The auscultatory signs which may be expected to be present are, metallic tinkling sounds, and a splashing or gurgling noise, produced by the action of the heart. Their connection with the heart is to be determined, if there be room for doubt, by requesting a momentary holding of the breath. They are not, however, invariably present, as shown by the case reported by Dr. Walshe. Tympanitic resonance on percussion over more or less of the præcordia is marked. In the case observed by Dr. Stokes, a distinct bruit de pot fêlé was observed; and in Dr. Walshe's case

1 On Diseases of the Heart and Aorta, Am. ed., p. 38.

variation in the relative position of tympanitic resonance and dulness, with change of posture.. The production of a peculiar noise, so loud as not only to be heard by the patient and others, but to prevent persons from sleeping in the same apartment, is a remarkable and highly distinctive feature in Dr. Stokes' case.

The physical signs, in connection with the history and symptoms, seem to be amply sufficient for the diagnosis. There is a possibility that considerable distension of the stomach with gas and liquid, may give rise to acoustic phenomena resembling those produced in some cases of pneumo-pericardium. But the evidences of pericarditis with effusion, under these circumstances, will be wanting. Cardiac gastric sounds, probably, require for their production that the pericardial sac shall be free from liquid. Again, metallic tinkling, and, possibly, splashing sounds may be produced by the action of the heart in some cases of pneumo-hydrothorax; but it is sufficiently easy to exclude the latter affection by the absence of its diagnostic signs.

The treatment of this variety of pericarditis does not claim distinct consideration.

PERICARDIAL ADHESIONS.

Inflammation of the pericardium, ending in recovery, involves, as has been seen, the formation of new tissue which often serves as a medium of permanent union of the opposed pericardial surfaces. Pericarditis, when general, i. e., when the inflammation extends over the whole, or the greater part of the membrane, is followed by this result, as inflammation of the pleura is followed by pleuritic adhesions. The pericardial adhesions now referred to, differ from those which have been considered as incident to a variety of chronic pericarditis. The latter are due to a stratum of lymph interposed between the surfaces of the pericardium, to which each pericardial surface becomes agglutinated. The lymph is unorganized, and is, in fact, equivalent to a foreign substance, at once separating and binding together, mechanically, the parietal and visceral portions of the pericardium. Under these circumstances, the pericardium is rarely, if ever, in a healthy condition. In adhesions by means of new tissue, the mode of union is quite different. It is by an or

ganized attachment. The new structure, when formed, becomes thereafter an integral portion of the organism. These adhesions. are not incompatible with a healthy state of the pericardial membrane; they do not necessarily constitute a disease, although they are the effects of disease. They become more and more firm with age. Some idea may be formed of the length of time since their formation, by the force required for their separation. It is customary to speak of them as more or less ancient. It is doubtful whether recovery from general pericarditis ever takes place without leaving more or less of these effects. The adhesion may be general or partial; in other words, the surfaces may be united over the whole heart, or only over a portion of the organ. General adhesion appears to be of much more frequent occurrence than partial. Of 70 cases analyzed by Louis, the adhesions were general in 60, and partial in 10; and of 86 cases analyzed by Dr. Chambers, 51 were universal, 4 nearly so, and 29 partial.' When the adhesion is general and close, the pericardium seems to be wanting, and it is conjectured that some of the cases reported by the early anatomists of absence of the pericardium, may have been cases of this description.

Pericardial adhesions are found, on examination after death, associated, in a certain proportion of cases, with valvular and other cardiac lesions. They are also found, not infrequently, when there had been no suspicion of cardiac disease. They denote, of course, that pericarditis has existed at some period during life, and this period may have been more or less remote from the time of death. They constitute, in a certain proportion of cases, the only abnormal condition which the heart presents. The practical questions connected with the subject are: What effects do they produce upon the heart and circulation, and how is their existence to be ascertained during life? These questions, it is obvious, are of considerable importance practically. They suggest the most convenient arrangement for the consideration of the subject.

What effects are produced by pericardial adhesions upon the heart and circulation?

Pathologists, for the most part, up to the present time, have regarded adhesions of the pericardium as constituting a very serious

'Decennium Pathologicum, Brit. and For. Med.-Chir. Rev., vol. xii. 1853. Also Bellingham, op. cit.