MODERN DEVELOPMENTS OF HARVEy's WORK. 461 



he left it to overlook the enormous extent to which it no\7 influences 

 our thoughts and actions, and thus to comjirehend its value very 

 imi)erfectly. 



As he himself says, " From a small seed springs a mighty tree; from 

 the minute gemn)ule or apex of the acorn, how wide does the giuirled 

 oak at length extend his arms, how loftily does he lift his branches to 

 the sky, how deeply do his roots strike down into the ground ! " ' 



How very minute is the gemmule from which has sprung everything 

 that is definite in medical science, for this gemmule is no other than the 

 idea which Uarvey records in these simple words, " I began to think 

 whether there might not be motion, as it were, in a circle." 



Out of this idea has grown all our knowledge of the processes of 

 human life in health and disease, of the signs and symptoms which 

 indicate disease, of the mode of ax^tion of the drugs and api)liances 

 which we use and the proper means of omi)loying them in the cure of 

 disease. In the works that have come dosvn to us we find that Harvey 

 developed his idea physiologically in several directions. lie discussed 

 its application to the absorption and distribution of nourishment 

 through the body, the mixing of blood from various parts, the main- 

 tenance and distribution of animal heat, and excretion through the 

 kidneys. How far he developed it in the direction of pathology and 

 therapeutics we do not know, as the results of his labors on these sub- 

 jects have, unfortunately, been lost to us by the destruction of his 

 manuscripts during the civil war. 



We are proud to reckon Harvey as an Englishman by birth, but he 

 is far too great to belong exclusively to any country; men of various 

 nations and scattered all over the face of the earth acknowledge him as 

 their teacher, and have played, or are playing, a part in developing his 

 discovery in its various branches of physiology, pathology, pharma- 

 cology, semeiology, and therapeutics. Americans, Austrians, Danes, 

 Dutchmen, Frenchmen, Germans, Italians, Norwegians, Russians, and 

 Swedes have all shared in the work, and so numerous are they that it 

 would be impossible for me to name them all. Stephen Hales, how- 

 ever, deserves si)ecial mention, for he was the first to measure the pres- 

 sure of blood in the arteries, and the resistance offered to the circula- 

 tion of the blood by the capillaries was investigated by Thomas Young, 

 a fellow of this college, who ranks with Harvey, Newton, and Darwin 

 as one of the greatest scientific men that England has ever produced, 

 and whose undulatory theory has been as fertile of results in physics 

 as Harvey's idea of circulation has been in physiology and medicine. 



Harvey's desire that those who had done good work should not be 

 forgotten was founded upon his knowledge of mankind, and of the tend- 

 ency there is to forget what has already been done by those who have 

 gone before us. The opposite condition often prevails, and the past is 

 glorified at the expense of the present. But sometimes the present is 



iThe Works of W. Harvey, Sydenham Society's edition, page 320. 



