present. I will only add further that clinical and pathological research are as much needed to-day as ever.
5. The blood, which is not only an essential part of the circulating system, but also of extreme importance in itself, and in relation to various pathological processes, has come within modern times into conspicuous prominence, and the investigations which have been carried out in connection therewith—both physiological and pathological—have revealed what may be truly described as a new world, transcending immeasurably anything which Harvey could have possibly imagined. Such investigations have of course necessitated the employment of particular methods of examination-physical, chemical, microscopical, with and without staining, and the use of special instruments and apparatus. The revelations of bacteriology may also be noted in this connection.
6. The Röntgen rays have been applied to the investigation of the heart and larger vessels, and their movements in health; and to the observation of morbid conditions of these structures, and of the pericardium. Without commenting on the application of this method for such purposes, it may be acknowledged that it has already proved useful within certain limits in adding to our knowledge on these points, and further information of importance may be reasonably anticipated from more prolonged and multiplied experience.
