last meeting, we considered how far the events of chronic lung-disease are influenced by the nature of -the morbid product, and by the part of the lung-structure invaded. I dwelt on the fact that affections which simply filled the alveolar cells with inflammatory products, without impairing the structure of the walls or in,eralveolar spaces, are capable of complete restoration; whereas alterations in the walls of the air-cells, and in that cellular tissue which contains and surrounds the

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... of the lung, ultimately leads, with almlost invariable result, to irreparable mischief in the part affected. As regards the products of irritation of lungtissue, whether we call them inflammation or tubercle, their ultimate changes also largely influence the progress and termination of every case. That which tends to speedy liquefaction is generally rapidly absorbed, as in acute pneumonia; while the process of caseation is incapable of absorption, and is prone to disintegration. Again, -the degenerative alterations in lung-tissue which tend to the production and increase of fibrous tissue of low vascularity lead to extreme chronicity; and, although incapable of restoration to a healthy state, are agents which oppose active destructive change, and thus counteract some of the most dangerous complications of chronic lung-disease. These several conditions must be regarded as the most potent factors in the story and complications of phthisis, anid serve to explain the many variations of that complex disease. But, viewing our cases clinically, there are several considerations which influence largely the course and termination of chronic disease ,of the lung; and I proceed to examine some of the most important of these. I desire to express, first, that it appears that the doctrine of the inflammatory origin of phthisis has of late years directed much more attention to the local (lisease in the lung. In former days (the Laennec period), the tubercular theory implied a pre-existing constitution, to which the tubercles in the lung owed their existence. This cachexia, involving the whole system, invaded the lung by a caco. plastic deposit, which was only a part of the ailment. The blood itself was supposed to be invaded; and, indeed, as we know, there is no organ of the body in which these tubercles are not found. Their inevitable tendency to degeneration and decay was held to be evidence of the depraved nature of the constitution in which they were found. Again, the whole malady was believed to be tubercle; and, tubercle being ineradicable and incurable, it followed that no amelioration of local disease could occur short of the destruction and removal of the materies morbi. Thus, when a tract of lung became dull with the other physical evidence of consolidation, the induration was attributed entirely to the tubercle. Certain shrewd observers, however (and among them my old teacher, Stokes), taught that the dulness in a portion of phthisical lung might be diminisheed by local depletion; and a portion at least of the exudation causing the dulness and impermeability was rightly attributed to inflammatory products of a temporary and removable nature. Here, indeed, was a near approach to the more modern German theory, that the whole of the lung-block is due to inflammation. I believe that the latter theory arose out of microscopical, and not from clinical, observation. Since it has been admitted that inflammnatory products are found in almost every case of phthisis, and that tubercle is often absent in many true cases of phthisis, there has been a gradual tendency in the profession to pay more attention than formerly to the lung; to study local changes of tissue and the varieties of local symptoms far-more than in the days of the preceding generation. This has had its good and its evil side; and I mention it here with the intention of examining how far purely local conditions influence the progress of our cases of chronic lung-disease. I do not believe that what is called the constitution which has led up to lungdisease can or ought ever to' be overlooked. There is no reason to believe that a healthy man acquiring a pneumonia should fall into phthisis, unless he had an underlying proclivity to changes in the walls of his air-cells and their surroundings. Shall we say an inborn tendency from heredity, or an acquired tendency to produce low rather than sthenic irritation in his lungs, owing to altered vital, or nerve, or blood-producing powers, the result of accidental influences, such as grief, overwork, or anxiety, or affections acquired rather than inherited, which have led the way to his phthisis ? But we know that local conditions have been more studied than formerly, and I would now enumerate some of the clinical observations which have arisen out of them. I have myself pointed out some of these many years ago; but others have since been added. Let us consider what symptoms are due to lung, and what to constitution diathesis, or whatever term represents systemic disorder apart from the reflected sympathies of the whole being with the localised irritation in his lung. This method will, perhaps, have the advantage of novelty in considering the events of phthisis. We and our fathers have, indeed, spent much time and labour in theorising over the abstraction which we call a constitution or diathesis, in order to account to ourselves satisfactorily for such events as fever, wasting and secondary disorders arising out of a malady whose earliest and latest structulral changes we find in the lung. But we have not advanced our practical treatment of the disease by such labours. We have multiplied so-called blood-remedies-nutrients which add to the pabulum of the chyle, such as oil or chemicals, such as hypophosphites and iron, which can alter and enrich the vital fluid; arid, in such treatment, our aim has confessedly been, not to reach the lung-disease, but to obviate, by a higher nutrition, the wasting effects on the system. I should be far, indeed, from discouraging such hypotheses, or opposing such treatment. It is at once the most scientific and successful imode of combating diseases whose result is a waste of vital power and of all bodily tissues. But, on the other hand, it was natural enough in those who hold the theory of the inflammatory nature of all chronic lung-i-ndurations to attribute the leading symptoms of a general nature, such as fever and wasting, to the sympathy of the system with a local irritation in the lung. Even the older pathologists have held that the hectic of phthisis is the measure of the lung-irritation. It is quite possible to imitate the hectic and wasting and all the symptoms of phthisis by an accidental irritation of the lung. I give the following case as a very practical illustration. Miss C., aged i8, of healthy parentage, and in perfect health, while at dinner, got a portion of the vertebra of a rabbit, on which she was dining, impacted in the right bronchus. Her distress and cough were for some days very great; and, although no effort was spared to induce expectoration of the bone by emetics and inverted posture, and other means, it remained so fixed. She had intense pain in the right subclavian region. At this point, a loud sibilant sound was heard on inspiration. In the course of a few weeks, she had wasted wonderfully; had a high temperature and pulse, with chills and night-sweats, and several times a streaky hoemoptysis; while a crepitant sound was heard at the seat of pain. Not to detail the whole of this interestiDg case, at the end of eighteen months she presented all the symptoms of advancing consumption, excepting that she had no secondary disorders of lung, nor of other organs. One day, during a violent fit of coughing, she expectorated a nearly perfect dorsal vertebra of a young rabbit; and from this time all her symptoms declined. She ceased to cough and expectorate, and regained flesh and vigour. A curious whistling sound on inspiration, with flattening of the chestwalls and fairly defined dulness, remained in the right subclavian region up to the latest time at which I saw her. At the present time, I have under my care a lady of about fifty, who was the subject of the same accident, a portion of mutton-bone becoming impacted in the left lung, as was evident from the physical signs. She was brought to me about two months after this occurrence, suffering from cough, with copious and occasionally fcetid expectoration, and frequent hoemoptysis. There wvas dulness with a large crepitation in the left subclavian region, not quite at the apex, but about opposite the third rib. She bad wasted, and was sweating, and had pain in the left chest. She described to me that, while at dinner, and in perfect health, she choked herself, and a piece of mutton-bcne " went the wrong way". As she had been previously healthy, I diagnosed impaction; and, to my gratification, this opinion proved correct, for about a week later she brought me the specimeni of bone (which I exhibit), which she expectorated after a severe fit of coughing with haemoptysis. She has recovered flesh, and has no fever; but still at times expectorates a quantity of muco-purulent matter, and has had several haemoptyses.