[Illustration: FIG. 25. THE PULMONARY ARTERY AND ADJACENT PART OF THE LUNG AND TRACHEA. The artery is completely occluded by a clot derived from a thrombus in the right auricle. (_Museum of the Middlesex Hospital._) Three-quarter size.] Somerville Hastings refers to a woman thirty-six years of age, anæmic from profuse, long-continued menorrhagia due to a uterine fibroid, who, whilst waiting in the hospital for hysterectomy, was seized with pulmonary embolism and died three hours later. An embolus occupied the pulmonary artery, resembling a blood-clot found in the left common and internal iliac veins. Hastings also states that in a patient who died from pulmonary embolism, after an operation, a thrombus occupied the right cardiac ventricle, and he thought it possible that this intraventricular clot furnished the embolus (Fig. 25). We must bear in mind that individuals apparently in good health die suddenly in the street, in the armchair, in a bath, or even during sleep: it is a fair assumption that some of the instances of sudden death occurring during convalescence from surgical operations may be due to failure of the heart absolutely unconnected with the operation. It is, however, undeniable that thrombosis of the pelvic veins after ovariotomy, or hysterectomy, is a source of fatal emboli. At present there is very little evidence available as to the cause of the thrombosis, but it can scarcely be doubted that sepsis, it may be only of a mild type, is responsible for some of the cases. A careful consideration of the matter reveals beyond any doubt that pulmonary embolism occurs much more frequently after hysterectomy or fibroids than after any other operation, and it is especially liable to happen in women who are profoundly anæmic from profuse and prolonged menorrhagia. This indicates that long-continued and irregular losses of blood induce some change in the composition of this important fluid, which favours its coagulation. It has been suggested that the practice of keeping patients strictly confined to bed for two or three weeks after hysterectomy and allied operations is responsible for the thrombosis which is the source of these fatal emboli. Some American surgeons act on this suggestion and insist on their patients getting out of bed a few days after such operations. This method does not commend itself to British surgeons. In my own practice I make it a rule, even in the most favourable conditions, to keep the patients confined to bed for two weeks. No patient is allowed up until her temperature has been normal for at least three days. The consequences of this practice appear to be justified, for in more than a thousand hysterectomies, only one of my patients lost her life in consequence of pulmonary embolism. In cases of embolism of the pulmonary artery, death does not always occur immediately, but may be postponed for an hour or more after the lodgment of the embolus.