WILLIAM TOWNSEND PORTER 93 



I do? The diagnosis and prognosis depend almost entirely 

 upon pathology, physiology, and anatomy, and the treat- 

 ment, so far as it is rational and not empirical, is the 

 expression of our knowledge of the physiological action 

 of the remedies employed. Medicine is a fire kindled 

 upon a tripod. It would be thrown down were either 

 anatomy, physiology, or pathology taken away. In heart 

 disease, for example, the diagnosis depends chiefly upon 

 the recognition of an increase in the size of the heart, and 

 of a change in the character of the heart sounds. How 

 could the dilatation of the heart be recognized were the 

 size and outlines of the healthy organ not accurately 

 known? To decide which valve gives forth the abnormal 

 sound, not only must the sounds in health be mastered, 

 but there must be precise knowledge of the course of the 

 blood within the chambers of the heart. To determine 

 how long the diseased heart will bear its burdens requires 

 a wide knowledge of the anatomy, physiology, and pathol- 

 ogy of the circulation and of the lungs, liver, and kidneys, 

 organs speedily affected by most disorders of the heart. 

 Anatomy, physiology, pathology, and practical medicine 

 meet at the bedside - - a blow at one is a blow at all ! 



The function of an organ cannot be learned by the con- 

 templation of its structure. The heart and the blood- 

 vessels were known to the ancients ; but the discovery of 

 the circulation of the blood waited fifteen hundred years 

 for Harvey's " frequent examination of many and various 

 living animals." : The thyroid gland had been known from 

 early times ; but the discovery of its function and the 

 consequent discovery of the remedy for myxedema and 

 cretinism was the fruit of recent experimentation upon 

 animals. 



Nor can the truth of physiology be taught without re- 

 course to living tissues. At a recent hearing before the 



1 Harvey: De Motu Cordis et Sanguinis in Animalibus. 



