4i8 



NA TURE 



[August 29, 1901 



to the time of Harvey it was supposed, and was com- 

 monly taught, that the heart acted Uke a suction pump, 

 not like a force pump ; that the diastole was the active, 

 the systole the passive, condition ; that the blood ebbed 

 and flowed in the veins and arteries ; that air and 

 vital spirits passed to the heart by the pulmonary 

 arteries ; that the blood, or part of the blood, passed from 

 the right ventricle to the left through pores in the 

 septum. Harvey's results were arrived at partly by 

 anatomical observation and inference, but chiefly by 

 physiological observation and experiment. His argu- 

 ments were founded, 



"not on general principles and analogies, but on the 

 results of ' frequent appeals to vivisection.' ' When first I 

 gave my mind to vivisection, as a means of discovering 

 the motions and uses of the heart, and sought to discover 

 these from actual inspection, and not from the writings of 

 others, I found the task so truly arduous, that I was 

 almost tempted to think, with Frascatorius ' (a Veronese 

 doctor of the sixteenth century and more a poet than a 

 man of science), ' that the movement of the heart was only 

 to be comprehended by God. For 1 could neither rightly 

 perceive at first when the systole and when the diastole 

 took place, nor when and where dilatation and contrac- 

 tion occurred, by reason of the rapidity of the movement, 

 which in many animals is accomplished in the twinkling 

 of an eye, coming and going like a flash of lightning.' 

 But the patient and prolonged study of the heart in many 

 animals showed him that 'the motion of the heart con- 

 sists in a certain universal tension, both of contraction in 

 the line of its fibres and constriction in every sense, that 

 when the heart contracts it is emptied, that the motion 

 which is in general regarded as the diastole of the heart 

 is in truth its systole,' that the active phase of the heart is 

 not that which sucks blood in but that which drives 

 blood out.'' 



In this way Harvey came to see clearly, what had been 

 already dimly guessed at by more than one of his fore- 

 runners, that the right heart receives blood from the 

 vena? cavae and pumps it through the lungs into the left 

 heart. From it there followed 



"another conception, which, however, 'was so new, was 

 of so novel and unheard of a character, that in putting it 

 forward he not only feared injury to himself from the 

 enmity of a few, but trembled lest he might have mankind 

 at large for his enemies.' . . . To this new view he was 

 guided by distinctly quantitative considerations. . . .This 

 is what he says ; ' I frequently and seriously bethought me, 

 and long revolved in my mind, what might be the quantity 

 of blood which was transmitted, in how short a time its 

 passage might be effected, and the like ; and not finding 

 it possible that this could be supplied by the juices of the 

 ingested aliment without the veins on the one hand being 

 drained, and the arteries on the other hand becoming 

 ruptured through the excessive charge of blood, unless 

 the blood should somehow find its way from the arteries 

 into the veins, and so return to the right side of the heart ; 

 I began to think whether there might not be a motion, as 

 if were, i>i a circle. Now this 1 afterwards found to be 

 true. . . .' To that true view of the motion of blood 

 he was led by a series of steps, each in turn based on 

 observations made on the heart as seen in the living 

 animal." 



His argument is essentially a physical mechanical 

 argument, and his demonstration was the " deathblow to 

 the doctrine of the distribution of 'animal spirits' by the 

 blood," although he does not himself deal with that 

 doctrine and only refers to it incidentally. 

 NO. I 66 I, VOL. 64] 



The revival of the study of physics under Galileo and , 

 his pupils in the seventeenth century had a marked in- j 

 fluence upon the progress of the new physiology, and ' 

 forms the subject-matter of the third lecture. In par- \ 

 ticular Borelli (1608-1679), the famous professor of ^ 

 mathematics at Pisa, influenced largely by his friendship • 

 with Malpighi, set to work to apply physical laws to 1 

 physiological problems. His great work, " De motu ' 

 animalium," was not published until just after his death, ' 

 but what is printed in it had been taught publicly long I 

 before, and much of the work had long been in manu- ' 

 script. ' 



A large part of Borelli's work is devoted to the special ' 

 mechanical problems. He treats in succession of 

 muscular mechanics, of standing, walking, running and '■ 

 locomotion in general, and investigates them by the' 

 aid of mathematics (his discussions concerning these 

 problems m.ny still be read with profit) ; he even attempts 

 to solve the nature of muscular motion by mechanical 

 methods. He estimates the force of muscles and of the ' 

 heart, shows how the elasticity of the arteries aids the ' 

 flow of blood through them, deals with the mechanics of 

 respiration, and anticipates the modern attempts to account ' 

 for all the phenomena of secretion by a mechanical 1 

 explanation. Even nervous phenomena are explained by 

 him as due to oscillations transmitted by a fluid, and in 

 the same spirit he discusses " the generation and nutrition ' 

 of both plants and animals, and even the nature of ' 

 several diseases. ... He was so successful in his me- 

 chanical solutions of physiological problems that many 

 coming after him readily rushed to the conclusion that 

 all such problems could be solved by the same methods." 



The work of Marcello Malpighi (1628-1694), the friend 

 of Borelli, and his colleague at Pisa during three years, . 

 although the greater part of his life was spent at Bologna 

 (his native city), is dealt with at great length in the fourth 

 lecture of the series. With his character the lecturer has 

 obviously the fullest sympathy. 



" Kindly even to softness, ready to give his aftections to 

 those who seemed drawn to him, devoted wholly to those 

 who had won his love, modest and retiring even to , 

 timidity, bold only in the interests of truth and right, never 

 in his own . . . beloved for the sake of himself, even by 

 those who were not competent judges of his talents and 

 his works." 



Four years of his life, viz, from 1662-1666, Malpighi 

 spent at Messina, as professor of medicine, and it was here 

 that he began those researches into the minute anatomy 

 of fishes and mvertebrates which "opened up in his mind 

 views as to the real nature of the like but more complex 

 structures of man and the higher animals." 



Malpighi's relations to the young Royal Society of 

 London are well known. These relations began in 1667 

 and continued throughout his life, and the Society "had 

 the honour of publishing and of bearing the expense of 

 publication of the greater part of Malpighi's works." His 

 work was essentially founded upon the use of the micro- 

 scope, which had but recently been invented, or rather 

 improved and rendered an instrument available for re- 

 search. He and Nehemiah Grew, independently and 

 almost simultaneously, laid the foundations of our know- 

 ledge of the structure of plants. He may also be re- 

 garded as the founder of embryology, for he gave the 



