398 THE POPULAR SCIENCE MONTHLY. 



to take an honest pride that such a man came of our English race ; and 

 as, I hope, to feel the deep responsibility which is laid upon us to have 

 a care that the stock which in the same hundred years bourgeoned out 

 in a Harvey and a Newton, shall not have its capacity for producing 

 like growths, in the present and in the future, starved by devotion to 

 mere material interests, or stunted by ignorant outcries against scien- 

 tific investigation. 



The second title which I have claimed for Harvey is that of author 

 of the " Exercitatio de Motu Cordis et Sanguinis." And that title is, 

 happily, quite indisputable. But some may suppose that I have so far 

 thrown myself into the spirit of my assumed office as to insert a super- 

 fluous appellation a sort of " Defender of the Faith." However, this 

 would be an error. Harvey might have discovered the circular course 

 of the blood; he might have given sufficient evidence of his discovery; 

 and yet he might have been quite incapable of writing that little essay 

 of fifty pages which no physiologist of the present day can read with- 

 out wonder and delight. For, not only is it a typical example of sound 

 scientific method and of concise and clear statement ; but, in addition 

 to the evidence of the course of the blood through the body, it contains 

 the first accurate analysis of the motions of the heart ; the first clear 

 conception of the mechanism of that organ as a pumping apparatus ; 

 the first application of quantitative considerations to a physiological 

 problem ; and the first deductive explanation of the phenomena of the 

 pulse and of the uses of the valves of the veins. " Libellus aureus," 

 Haller called it and never was epithet more aptly bestowed. 



Harvey's third title to honor is the authorship of the " Exercitationes 

 de Generatione." In this treatise Harvey grapples with two of the 

 most difficult problems of biology the physiological problem of gener- 

 ation and the morphological problem of development. It was simply 

 impossible that he should solve these problems, for they can be ap- 

 proached only through the microscope ; and Harvey was dead before 

 Hooke, Malpighi, Swammerdam, orLeeuwenhoek, the fathers of micros- 

 copy, began their work. He saw the circulation in shrimps " ope perspi- 

 cillo" indeed but the perspicillum was a mere hand-glass. Hence it is 

 not wonderful that Harvey's theory of fecundation is altogether erro- 

 neous ; and that he is no less mistaken respecting the nature of the 

 parts of the embryo which first make their appearance and the mode of 

 their formation. 



Nevertheless, just as it is the fate of dullness to be blind to the 

 significance of justly-observed facts, so is it the rare privilege of men 

 of the highest genius to discern the true light among the ignes fatui of 

 error. They know the truth, as Falstaff discerned the true prince 

 among his pot companions, by instinct. Explain the matter how we 

 will, it is an indubitable fact that, though Harvey's fundamental observa- 

 tions were either inadequate or erroneous, some of his most important 

 general conclusions express the outcome of modern research. 



