has continued for many years without becoming complicated with any other indication of disease, have induced me to modify that opinion. It is true that I have certainly often observed wavy inspiration at one part of the chest when pectoriloquy or cavernous respiration could be elsewhere detected, or when other indications, local or general, of advanced consumption have been present; and in a greater number of instances the wavy inspiration has been superseded by the occurrence of bronchial respiration, dulness on percussion, dry crepitation (crackling), or other more or less decided evidences of the establishment of phthisis; but, in a still greater proportion of cases it has continued, for a considerable period, to be the only important evidence of deviation from the natural state. Often indeed I have watched the symptom for years without observing any transition to serious disease. Of 105 cases, carefully recorded in the course of an investigation which I formerly made regarding this symptom, thirty-two afforded grounds for suspecting tubercular disease; such, for example, as dulness on percussion, or prolonged expiratory murmur. In twenty-two hæmoptysis had occurred. In three, a murmur could be heard over the pulmonary artery. But, of the remainder, many were not affected even with cough, and their complaints were usually expressed in general terms as of "delicate health," " easy fatigue," or, if they made any reference to the chest, it was seldom of anything beyond slight oppression of respiration-or of "seeming to breathe through thin cambric." It is therefore reasonable to conclude that, if this form of interrupted inspiration be an indication of tubercular disease, it is.

the earliest local sign with which we are acquainted. The question, however, naturally occurs, can this symptom depend on mere functional disturbance, and disappear, leaving the subject of it in apparent health? Having devoted some attention to this inquiry, I must acknowledge that although wavy inspiration, when dependent on pleurisy, bronchial affection, or rheumatism, may disappear, I have not satisfied myself of its removal (unless superseded by more serious symptoms) in any instance unconnected with the conditions which I have specified. To what cause then can the production of so persistent a phenomenon be attributed? The sensation conveyed to the ear suggests the idea of some obstruction in the pulmonary tissue, yielding at gradual intervals to the admission of air. The persistency of the sign points to some organic change, whilst its frequently stationary character encourages the belief that such change is not necessarily tubercular.

Sufficient opportunities have not occurred for conclusively testing any hypothesis, but the explanation which would appear best calculated to meet the conditions would assume the existence of an exudation, less albuminous than tubercle, less fibrinous than the usual product of common inflammation, about the walls of the small bronchial tubes, and the interstices of the pulmonary substance, calculated to impair the elasticity of the surrounding structure.

The frequent existence of such an exudation is not a matter of speculation; it is, indeed, described by Rokitansky as not infrequent. We may suppose that such morbid product of low inflammation may sometimes be sufficiently plastic to become organised, and

to constitute hypertrophy of the cells and lobules, without involving any serious pulmonary disorganisation or constitutional disturbance. In other instances it may be associated with the germs of true tubercle, or become a favourable nidus for tuberculous deposit. When, indeed, distinct manifestations of phthisis appear in patients exhibiting this sign, the disease usually advances with marked rapidity. We may form an approximative idea of the proportionate degree of probability of such a course, from the relative frequency of the occurrence of hæmoptysis. We may assume this symptom to occur in half the cases of phthisis in the first stage, as determined by recognised signs. I have formerly stated that it occurs in about a third of those cases in which prolonged expiratory murmur was the principal physical sign; and in the cases which I have analyzed, chiefly characterised by wavy inspiration, hæmoptysis occurred in about a fifth.

As tending indirectly to support the view now suggested of the pathology of this symptom, we may specify the large proportion of such patients engaged in outdoor occupations. You will observe, amongst the patients I have introduced to you to-day, that the three men are all engaged in out-door occupations. Of the cases which I formerly recorded as examples, a very large proportion was composed of gardeners, policemen, coachmen, sailors, and toll-collectors.

The more frequent occurrence of the sign under consideration, on the left side, is worthy of notice, and the cause not easy to determine. Its occasional presence on the right side alone, independent of other considerations, is unfavourable to any hypotheses which

would refer it to the action of the heart, or to a disproportion of the respiratory to the circulating power. If a morbid deposit be engaged in the production of the wavy inspiration, it would seem that such deposit must be most apt to occur on that side of the chest; but the more direct course of the right bronchial tube, and the excess of diameter of the three branches on the right side, over that of the two branches on the left, by facilitating the ingress of air, may render a greater amount of obstruction necessary to establish an interrupted murmur on the right side.

It would be a great advantage, to be able to detect tuberculosis of the blood, prior to the establishment of any real tubercular disease. With this view, I have from time to time availed myself of the microscope in order to ascertain whether any difference could in this way be detected between the blood of the phthisical and that of healthy individuals. You are perhaps aware, that when a drop of blood taken from a suitable part, the finger for example, is placed on the glass for examination, the corpuscles, after a period, varying much in duration in different subjects, often exhibit a change of outline; the discs becoming mulberry-like in form, then stellated or corrugated, as delineated in the drawing,* in the preparation of which I have been politely assisted by Mr. Quekett. The promptness of this change, as before observed, varies. It is probably accelerated in healthy individuals by exercise or any circumstance which quickens the pulse; but I have satisfied myself, that quickness of the circulation is not the only cause of the phenomenon; as far as I have *Plate I. Fig. 2.

yet observed, it would appear to occur more quickly in consumptive than in healthy persons, and more quickly in some consumptive patients, although at a corresponding stage of the disease, than in others; and I am inclined to think, that those patients are most likely to improve whose blood is longest undergoing this particular change. H. I. C. afforded an interesting illustration of this remark: as may be frequently observed in the blood of consumptive individuals, there was a considerable number of large colourless corpuscles, but the ordinary blood corpuscles, whether forming rouleaux or otherwise, preserved their individuality for a long period, and the discs did not assume a crenate outline after the lapse of three quarters of an hour; and this patient, although afflicted with phthisis in the second stage on the left, and the third on the right side, was discharged from the hospital materially improved.

In some unfavourable cases, the blood discs almost immediately lose their characteristic form, and seem to melt into a confused mass, as is said to have been observed in the blood of the spleen, and as I have noticed in a patient undergoing a severe course of mercury. In such instances the disease may be expected to advance rapidly. Observations of this kind are liable to many fallacies; since it is possible that temporary causes, such for example as mental emotion, may modify the results; still I recommend the inquiry to your attention, as worthy of regard when pursued concurrently with other modes of investigation.

In tracing the early indications of consumption, you will observe that I have particularly recorded the measure of respiratory power denominated "vital capacity,"