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THE POPULAR SCIENCE MONTHLY.— SUPPLEMENT. 



Van den Spieghel, or Spigelius, as he called 

 himself, in accordance with the fashion of those 

 days, died comparatively young in 1625, and his 

 work was edited by his friend Daniel Bucretius, 

 whose preface is dated 162*7. The accounts of 

 the heart and vessels, and of the motion of the 

 blood, which it contains, are full and clear ; but, 

 beyond matters of detail, they go beyond Galen 

 in only two points, and, with respect to one of 

 these, Spigelius was in error. 



The first point is the "pulmonary circula- 

 tion," which is taught as Columbus taught it 

 nearly eighty years before. The second point is, 

 so far as I know, peculiar to Spigelius himself. 

 He thinks that the pulsation of the arteries has 

 an effect in promoting the motion of the blood 

 contained in the veins which accompany them. 

 Of the true course of the blood as a whole, Spi- 

 gelius has no more suspicion than had any other 

 physiologist of that age, except William Harvey ; 

 no rumor of whose lectures at the College of | 

 Physicians, commenced six years before Spieghel's 

 death, was likely in those days of slow communi- 

 cation, and in the absence of periodical publica- 

 tions, to have reached Italy. 



Now, let any one familiar with the pages of 

 Spigelius take up Harvey's treatise and mark the 

 contrast. 



The main object of the " Exercitatio " is to 

 put forth and demonstrate, by direct experimental 

 and other accessory evidence, a proposition which 

 is far from being even hinted at, either by Spi- 

 gelius, or by any of his contemporaries or prede- 

 cessors ; and which is in diametrical contradiction 

 to the views, respecting the course of the blood 

 in the veins, which are expounded in their works. 



From Galen to Spigelius, they one and all 

 believed that the blood in the vena cava and its 

 branches flows from the main trunk toward the 

 smallest ramifications. There is a similar con- 

 sensus in the doctrine, that the greater part, if 

 not the whole, of the blood thus distributed by 

 the veins is derived from the liver ; in which 

 organ it is generated out of the materials brought 

 from the alimentary canal by means of the vena 

 porta?. And all Harvey's predecessors further 

 agree in the belief that only a small fraction of 

 the total mass of the venous blood is conveyed by 

 the vena artcriosa to the lungs and passes by the 

 arteria venosa to the left ventricle, thence to be 

 distributed over the body by the arteries. Wheth- 

 er some portion of the refined and "pneumatic" 

 arterial blood traversed the anastomotic chan- 

 nels, the existence of which was assumed, and so 

 reached the systemic veins, or whether, on the 



contrary, some portion of the venous blood made 

 its entrance by the same passage into the arteries, 

 depended upon circumstances. Sometimes the 

 current might set one way, sometimes the other. 



In direct opposition to these universally re- 

 ceived views, Harvey asserts that the natural 

 course of the blood in the veins is from the pe- 

 ripheral ramifications toward the main trunk ; 

 that the mass of the blood to be found in the 

 veins at any moment was, a short time before, 

 contained in the arteries, and has simply flowed 

 out of the latter into the veins ; and, finally, that 

 the stream of blood which runs from the arteries 

 into the veins is constant, continuous, and rapid. 



According to the view of Harvey's predeces- 

 sors, 1 the veins may be compared to larger and 

 smaller canals, fed by a spring which trickles 

 into the chief canals, whence the water flows to 

 the rest. The heart and lungs represent an en- 

 gine set up in the principal canal to aerate some 

 of the water and scatter it all over the garden. 

 Whether any of this identical water came back 

 to the engine or not would be a matter of chance, 

 and it would certainly have no sensible effect on 

 the motion of the water in the canals. In Har- 

 vey's conception of the matter, on the other 

 hand, the garden is watered by channels so ar- 

 ranged as to form a circle, two points of which 

 are occupied by propulsive engines. The water 

 is kept moving in a continual round within its 

 channels, as much entering the engines on one 

 side as leases them on the other ; and the mo- 

 tion of the water is entirely due to the engines. 



It is in conceiving the motion of the blood, 

 as a whole, to be circular, and in ascribing that 

 circular motion simply and solely to the contrac- 

 tions of the walls of the heart, that Harvey is so 

 completely original. Before him, no one, that I 

 can discover, had ever so much as dreamed that 

 a given portion of blood contained, for example, 

 in the right ventricle of the heart may, by the 

 mere mechanical operation of the working of that 

 organ, be made to return to the very place from 

 which it started, after a long journey through 

 the lungs, and through the body generally. And 

 it should be remembered that it is to this com- 

 plete circuit of the blood, alone, that the term 

 " circulation " can, in strictness, be applied. It 

 is of the essence of a circular motion that that 

 which moves returns to the place whence it 

 started. Hence, the discovery of the course of 

 the blood from the right ventricle, through the 



1 See the comparison of the veins to the canals 

 for irrigating: a garden, in Galen, " De Naturalibus 

 Facultatibus," vol. iii., cap. xv. 



