Now we are in a position to study the tobacco heart in a man of 40; and again let us begin with a man who is sound, active, and healthy otherwise. He complains of his heart, and recognises willingly (for he belongs to our own profession), in the discomfort and anxiety from which he suffers, the penalty of having smoked for years the strongest and blackest tobacco that he could buy. Yet his heart is not enlarged, and the cardiac sounds might be described as ordinary were they not peculiarly irregular, the frequency changing every moment and a falter occurring at short intervals. There is not a trace of murmur to be found in connection with the valves and orifices. At ages over 40 a clinical study of the tobacco heart is highly instructive from a practical point of view. Whilst palpitation is still the common complaint, pain, including angina, is put forward more prominently, and so are faintness, actual faints, a feeling of impending death, and a sense of cardiac irregularity, each intermission being accompanied with a sudden stab through the præcordia. Some of you will remember Mr. Barrie's quaint account in 'My Lady Nicotine' of what he calls the horrors of his smoking days, when the pain at his heart made him hold his breath--"a sting" as he describes it, and he believed he was dying. In these subjects the heart is more frequently found to be large and feeble; the same weak systolic murmur is occasionally to be heard; the radial pulse is often irregular, and the vessel wall naturally thick. This, you will notice, is a combination of symptoms and signs sufficient to alarm the casual observer. But when we examine it more deliberately, in the light of our study of the tobacco heart in young subjects, on the one hand, and of our knowledge of the normal or natural condition of the heart and arteries at 60, on the other hand, we are able to reassure ourselves and our patients. We are justified in concluding not only that every cardio-vascular lesion which may be found in tobacco smokers is not to be put to the credit of tobacco, but, _vice versâ_ (and this is of more interest to us in our present inquiry), that every præcordial pain, angina, faintness, or irregular pulse in a man of 60 with a full-sized heart is not to be hastily regarded as evidences of grave disease without further inquiry as to his habits. The cardiac enlargement and large pulse may be nothing more than the result of a life of bodily and mental activity: the præcordial distress may be the result only of tobacco. How very necessary this caution is will be impressed upon your consideration by the two following cases. The first is that of a man of 60, actively engaged in professional pursuits, who first suffered from præcordial pain of an alarming character four and a half years ago, and has had attacks since, particularly during exertion and after meals. One day last autumn, at the end of many hours' hard work, cheered by at least 18 cigarettes, he was rushing off to dine