PHYSIOLOGY - SCIENTIFIC RESULTS TRACEABLE TO ANIMAL EXPERIMENT.
Passing over the fundamental knowledge gained in this way on the heart and circulation by William Harvey, Stephen Hales and John Hunter we have learned by animal experiment to measure accurately the work done by the heart and, by studying the man ner in which this work is affected by different conditions, we can increase or diminish it according to the needs of the organ. Experiments in that part of physiology which deals with muscle and nerve have thrown light on the wonderful process of "com pensation" by which a diseased heart is able to keep up a nor mal circulation. Similarly, the flow of chyle along the lacteals and thoracic duct, the part played by the stomach, the liver, the pancreas and the intestinal glands, respectively, in digestion, the growth of bone, the functions of certain parts of the brain, of the sympathetic system, of nerves (including their regeneration after injury), reflex action, the mechanism of respiration, the influence of endocrine glands, the action of vitamins have all depended upon animal experiment. Indeed it is impossible to think of any advance in physiological knowledge which is not directly or indirectly traceable thereto. Even the recent isolation of insulin, in itself a matter of chemistry, was led up to by observation that removal of the pancreas in dogs is followed by permanent diabetes.