Page:The advancement of science by experimental research - the Harveian oration, delivered at the Royal College of Physicians, June 27th, 1883 (IA b24869958).pdf/35

31 a mercurial one. More recently, Volkman and Ludwig, have advanced our knowledge of the subject, but, perhaps the most in- teresting investigations of later times in connection with the circulation have been those of Claude Bernard, who has shewn that section of the cervical sympathetic on one side of the neck was followed by a rise in the temperature and by dilatation of the blood vessels on the same side; on these experiments followed the discovery of the inhibitory action of the pneumogastric nerve on the heart itself.

Leaving these facts connected with the circulation, let us turn for a few moments to one of the most ardent students of nature of recent times, most patient in observation, diligent in research, an investi- gator of those minute circumstances which are often the guide to clearer truth, a pro- found philosopher on whom this college delighted to confer the highest honour as a physiologist. I refer to Darwin; his facts are wonderful and entrancing, his deduc- tions are not proven. What is more pleasant than to study his observations on plants