his clinical observation, provided he takes the trouble to carry out adequate systematic investigation in each individual case. On the other hand the fact must not be ignored that there are certain changes affecting the heart or vessels, which it may be very difficult or even impossible to make out definitely during life, and hence we must still be prepared to meet with cases of sudden death from cardiac failure, or fatal secondary vascular lesions, the nature and cause of which can only be revealed by post mortem examination, even if then.
1. One obvious and striking advance which has been made is in the recognition, and more methodical observation and practical study, of symptoms associated with diseases of the heart and vessels. No doubt time was when the relationship of the more important of these phenomena to the circulatory system was not in the least appreciated or understood, and only by degrees, as physiological and pathological knowledge became developed and established on the basis of scientific investigation and practical observation, was the connection worked out and verified. It cannot be too strongly enforced that the comprehensive and intelligent study of symptoms which happen to be present in any case of cardiac disease, whether immediately associated with the heart, or due to the remote or secondary effects of the existing morbid conditions, is still of essential importance from different aspects. On the
