5 24 THE POPULAR SCIENCE MONTHLY. 



vapors by the act of expiration, the mixture being now complete 

 in every respect, and the blood become fit dwelling-place of the 

 vital spirit, it is finally attracted by the diastole, and reaches the 

 left ventricle of the heart." He then goes on to give as proofs of 

 the accuracy of his statements (1) the various conjunctions and 

 communications of the pulmonary artery and pulmonary vein in 

 the lungs, and (2) the great size of the pulmonary artery, and the 

 great quantity of blood passing through it; both being much 

 larger than would be required for the mere nutrition of the lungs. 

 He concludes that the septum, seeing that it is without vessels and 

 special properties, is not fitted to permit the communication in 

 question, " although," he adds, " it may be that some transudation 

 takes place through it." * This unfortunate qualification of what 

 he has so distinctly affirmed just before namely, that the com- 

 munication does not take place through the septum is not very 

 intelligible ; for if he believed the blood to soak through the sep- 

 tum, his theory differs but little from that of Galen, and yet Ser- 

 vetus calls attention to the fact that what he is declaring was 

 unknown to Galen, f 



Prof. Huxley J points out that Servetus quotes neither observa- 

 tion nor experiment in favor of the imperviousness of the septum. 

 But neither does Realdus Columbus,* who correctly described the 

 lesser circulation in 1559, and to whom the credit of the discovery 

 was very early ascribed. || It is to be remembered that the work 

 in which Servetus introduces his discovery is not a treatise on 

 physiology, and that the whole passage being brought in by way 

 of illustration is not fully treated. 



It is clear, however, that Servetus held (1) that the blood in a 

 great stream passes from the right ventricle of the heart to the 

 lungs ; (2) that in the lungs, and not in the left ventricle, it is 

 purified; and (3) that from the lungs it passes by the pulmo- 

 nary vein to the left ventricle of the heart and thence into the 

 arteries. 



From these statements of fact Servetus quickly passes to meta- 

 physical speculations. He has before said : " There are three sorts 

 of spirits in the human body namely, natural, vital, and animal 

 which are not in reality three, but two distinct spirits only ; the ar- 

 teries communicating by anastomoses, the vital spirit to the veins, 

 in which it is called natural. The first spirit then is the blood, 

 whose seat is in the liver, and in the veins of the body ; the sec- 

 ond is the vital spirit, whose seat is the heart and arteries ; the 



* " Licet aliquid resudare possit" Christ. Eestit., p. 171. 

 f Christ. Restit., p. 171. 



\ Fortnightly Review, February, 1878. 



* De Re Anatomica Realdi Columbi Cremonensis, 1559, p. 177. 

 Opera Chirurgica Ambrosii Parsei, 1594, p. 116. 



