plicable,-pretty frequently occur. It would be difficult to describe or explain, for instance, the varieties of quality found in the first sound of soft, flabby, fatty hearts, with (practically speaking) sound valves. Clearness and elevation of pitch depend, as a rule, either on thinness of the muscular walls, or on predominance of the valvular element of the sound.

The first sound sometimes possesses a peculiar full-toned quality, without the least sharpness, while it is strongly accentuated at the commencement, and commonly prolonged; the nearest articulate symbol of the two sounds under these circumstances appears to be b'oom tup, pronounced with strong emphasis on the b. I have observed this peculiarity in cases of eccentric hypertrophy of the left ventricle,-but without ascertaining the special condition on which it depends.

The quality of the first sound at the apex is sometimes sharply knocking; but with care this knocking quality is separated by the ear from the true heart-sound, and obviously depends on the impulse of the apex against the side,-but not necessarily against the inferior border of the fifth rib, as fancifully imagined by Hope. Knocking impulsive sound cannot be called an essential or even habitual attendant on any particular disease of the heart; nervous palpitation (especially if the edge of the lung be by some disease of its own carried unduly towards the left) will readily produce it in a sound organ. Thin-walled resonant chests supply it with greater ease than others; and morbid induration of the heart's apex, or calcification of the pericardium, will aid in intensifying it. The heaving and steadily pushing character of the impulse in simple hypertrophy prevents its occurrence in that disease: eccentric hypertrophy is the form of enlargement it most frequently accompanies.

The first sound is sometimes slightly rough, and approaching in quality to a murmur at the apex; it is, in fact, murmurish, without being actually converted into a murmur. *This may be (a) a persistent condition, observable week after week, while the patient remains under treatment; or (b) a temporary state, constantly noticeable for a few days, and then disappearing; or (c) a mere transient phenomenon, occurring with some, absent from other beats of the heart. In the first case (a,) it has appeared to me referrible to an incipient or slight amount of

In the case already referred to (p. 188,) when the contraction of the abdominal muscles occurs in a slow vermicular manner, the sound is distinctly of murmur-like quality.

*

some one of the organic conditions, which carried further, produce a perfect systolic murmur; or, probably, sometimes to a buzzing murmur-like quality in the muscular sound itself, produced by slow contraction of the fibres, or some special alteration of their texture. The second case (b) is exemplified by some excessively rare instances of acute rheumatism, where the systolic sound of the left apex, roughened and murmurish for a few days at the outset, then loses this quality, either permanently, or to resume it again at a later period in a more decided form. Passing vascular roughness of the mitral, or even ventricular, endocardium, and imperfect closure of that valve from the influence of irritation, suggest themselves as possible causes of the phenomenon; but anatomical evidence is of course wanting on the point. In the third case, (c) the peculiarity is caused either by coincidence of the respiratory sound with that of the heart, or by rubbing of the apex against the pericardium,‡ or by movement of air in the adjoining lung-substance produced by the cardiac impulse, or (by far the most important cause, because the most likely to lead to error,) by a tendency to reduplication of the first sound.

The second sound at the base is rendered dull, and comparatively clanging, by fibro-fatty thickening, without insufficiency, of the sygmoid valves. Diminished elasticity of the arterial

walls has a similar effect.

Like the first the second sound may be murmurish, temporarily or permanently. Very trifling insufficiency will probably thus modify its quality; whether marked reticulation of the valves will suffice for the purpose will hereafter be discussed. The most common cause of murmurishness in this sound is a tendency to reduplication.

The natural accentuation of the sounds, as shown in a previous page, is liable to numerous perversions; but as the accent falls on whichever sound is intensified, and mainly at the spot of intensification, repetition may be saved by referring the reader to the paragraphs on augmented intensity. When the heart is weak and flabby from organic change, or from want of tone (as in continued fever,) there may be a total deficiency of

*Case of James Hayes. U. C. H., Oct. 1850.

It is sometimes impossible to satisfy oneself on this point, unless by causing the patient to suspend his breathing.

The more superficial character and the influence of change of posture will generally distinguish this variety from a true murmurishness.

accent on either sound at the apex ;* the sounds resemble those of a vibrating pendulum.

Like the sounds, the silences vary in disease in relative duration. The first (or post-systolic) silence is lengthened by deficient elasticity of the arterial walls, whereby the recoil of the blood on the valves is sluggishly effected; so, too, whenever the first sound is disproportionately shortened (this is, perhaps, best observable in continued fever) the first silence is lengthened. The first silence is normally so short, that it is difficult to appreciate its decrease.

The second (or post-diastolic) silence is lengthened in cases of advanced constriction of the mitral orifice; the process of filling the ventricle is laborious and slow, and hence the systole lags, as it were, behind its time. When the circulation is greatly slackened, the second silence is generally disproportionately prolonged.

The relationship of the sounds of the heart to the pulse varies in disease. In the normal state, the first sound is apparently synchronous with the diastole of the arch of the aorta, the pulmonary, carotid, and subclavian arteries; thenceforth, the further the vessel from the heart, the more distinct is the interval between the systolic sound of that organ and the arterial diastole. It is difficult to determine the possible length of interval consistent with health; but it may be affirmed, that if the diastole of the most distant vessels, as the posterior tibial and dorsal artery of the foot, is so much retarded as to become synchronous with the second sound, the state is morbid. This retardation, which was first detected by Dr. Henderson as an attendant on insufficiency of the aortic valves, may (with care) be detected in many, but unquestionably not in all, cases of that disease. Possibly where no morbid retardation can be discovered, the failure may depend, not on its absence, but on its being carried to such extremes, that the arterial pulse produced by one cardiac systole is nearly synchronous with the next. The only fact, however, I know of, supporting this idea, is, that it is in extreme cases of aortic regurgitation that the pulse seems occasionally to stand in normal relationship of time to the heart's systole. The same sign exists in attenuated dilatation of the left ventricle also. Again, in health, the frequency of the pulse, and the length of the systolic sound vary inversely as

*The second sound is in certain rare cases of mitral regurgitation, so intensified that the accent falls on it, even when ausculted at the apex.

each other: a frequent pulse is the index of a short first sound, and vice versa. The same relationship holds good in some morbid states; for example, in anæmia and in the re-action after hemorrhage: it is, on the other hand, occasionally perverted; the pulse may be infrequent, and the systolic sound short. In fatty degeneration, and in simple flabby softening of the heart, this perversion may sometimes (though rarely) be noticed.

The sounds of the heart are sometimes suspended for the precise length of time occupied by an ordinary revolution of the organ: they are said then to intermit. Very commonly such intermission recurs with considerable regularity; that is, after a fixed number of regular beats. Sometimes the systolic sound seems to anticipate, sometimes, on the contrary, to hesitate at the proper moment of its occurrence-changes of rhythm closely connected with shortening or prolongation of the second silence. Sometimes a series of feeble and rapidly succeeding sounds follows others comparatively loud, slow, and deliberate; and there may be a certain uniformity in the number of each kind, and in the periods of their recurrence. Or the irregularity of the sounds (as of the contractions) may be complete, both in intensity and in rhythm, no two revolutions corresponding to each other in either character: there ceases to be any semblance of order in disorder. This excessive perversion exists in highly marked mitral contraction and regurgitation, in extreme softening (acute and chronic,) fatty infiltration, acute destruction of a portion of a valve, or of chordæ tendineæ, rupture of these structures, formation of fibrinous coagula within the heart, and in a small proportion of cases of pericarditic effusion.

The natural correspondence in the number and time of cardiac systoles and arterial pulsations is habitually maintained, even when the rhythm of the heart's contractions is thus variously altered. If the left ventricle intermits, or anticipates, or hesitates, or becomes wholly irregular in its contractions, a precisely similar change occurs in the arterial pulses: the impulses of the connected tubes are the counterparts of those of the central organ. But, on the other hand, there may be a failure of this correspondence, not only when the heart's contractions are thus abnormal in rhythm, but even when they are in this respect normal. Thus two revolutions of the heart may correspond to a single radial pulse, the cardiac action and the pulse being perfectly regular in force and rhythm; or the pulse may be perfectly regular, and the heart's successive systoles somewhat unequal

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in force and duration, as in a case formerly recorded,* where eighty-eight systolic contractions produced forty-four radial pulsations. Here the rhythm of each pair of beats of the heart might be represented thus:-Systole 5, diastole 3; systole 9, diastole 4. It was the first of the two systoles that failed to affect the pulse at the wrist; and as there was no evidence of aortic or mitral disease, but merely of flabby enlargement, that systole may have been simply too weak to influence the distant vessels: the state was of temporary duration. I have observed a similar condition, persistent, but of less regular type, in cases of extreme contraction of the mitral orifice: under these circumstances, doubtless the systole occasionally takes place before the ventricle is supplied with blood to propel.

Again, in certain cases of utter irregularity of the sounds, there may be no traceable accordance between them and the force or rhythm of the pulse. This is, perhaps, best observable where the irregularity comes on suddenly from rupture of a valve, or accumulation of coagula in the cavities; but is occasionally met with in all the diseased states productive of irregularity.

The number of sounds attending each beat of the heart may vary, the arterial pulse holding its natural relationship to the systole. A single sound only may be heard, and this may be the first or the second; whichever sound be deficient in any particular spot, it may, or may not, be audible at some other part of the cardiac region. The first sound may be quasi-deficient at the left apex, when the conditions already described as weakening it are carried to extremes; but it will then be found at the right apex, and at the base. So, again, the second sound may be quasi-deficient at the base from excessive feebleness, or from being covered by a prolonged systolic sound, or systolic murmur; but in the first case, excitement of the heart, increasing the energy of its contractions, will invigorate the sound, and in the second case, the sound will be heard at the right apex. Absolute deficiency of either sound (or of a murmur taking its place) has never fallen under my observation; in other words, neither systole nor diastole has ever been, in my experience, absolutely noiseless.

Reduplication of the first sound at the apex is not a very uncommon condition: the articulate symbol of the sounds may *Clin. Lect., loc. cit. p. 443.