That Servetus was only acquainted with the pulmonary circulation, has been the general opinion. Portal, though in one place he speaks with less precision, repeatedly limits the discovery to this; and Sprengel does not entertain the least suspicion that it went farther. Andrès (xiv. 38), not certainly a medical authority, but conversant with such, and very partial to Spanish claimants, asserts the same. If a more general language may be found in some writers, it may be ascribed to their want of distinguishing the two circulations. A medical friend who, at my request, perused and considered the passage in Servetus, as it is quoted in Allwoerden’s life, says in a letter, “All that this passage implies which has any reference to the greater circulation, may be comprised in the following points:—1. That the heart transmits a vivifying principle along the arteries and the blood which they contain to the anastomosing veins; 2. That this living principle vivifies the liver and the venous system generally; 3. That the liver produces the blood itself, and transmits it through the vena cava to the heart, in order to obtain the vital principle, by performing the lesser circulation, which Servetus seems perfectly to comprehend.
“Now, according to this view of the passage, all the movement of the blood implied is that which takes place from the liver, through the vena cava to the heart, and that of the lesser circulation. It would appear to me that Servetus is on the brink of the discovery of the circulation; but that his notions respecting the transmission of his ‘vitalis spiritus,’ diverted his attention from that great movement of the blood itself, which Harvey discovered.... It is clear, that the quantity of blood sent to the heart for the elaboration of the vital spiritus, is, according to Servetus, only that furnished by the liver to the vena cava inferior. But the blood thus introduced is represented by him as performing the circulation through the lungs very regularly.”
It appears singular that, while Servetus distinctly knew that the septum of the heart, paries ille medius, as he calls it, is closed, which Berenger had discovered, and Vesalius confirmed (though the bulk of anatomists long afterwards adhered to Galen’s notion of perforation), and consequently, that some other means must exist for restoring the blood from the left division of the heart to the right, he should not have seen the necessity of a system of vessels to carry forward this communication.
To Columbus. 14. Columbus is acknowledged to have been acquainted with the pulmonary circulation. He says of his own discovery, that no one had observed or consigned it to writing before. Arantius, according to Portal, has described the pulmonary circulation still better than Columbus, while Sprengel denies that he has described it all. It is perfectly certain, and is admitted on all sides, that Columbus did not know the systemic circulation: in what manner he disposed of the blood does not very clearly appear; but, as he conceived a passage to exist between the ventricles of the heart, it is probable, though his words do not lead to this inference, that he supposed the aerated blood to be transmitted back in this course.[648]
[648] The leading passage in Columbus (De Re Anatomica, lib. vii., p. 177, edit. 1559), which I have not found quoted by Portal or Sprengel, is as follows: Inter hos ventriculos septum adest, per quod fere omnes existimant sanguini a dextro ventriculo ad sinistrum aditum patefieri; id ut fieret facilius, in transitu ob vitalium spirituum generationem demum reddi; sed longa errant via; nam sanguis per arteriosam venam ad pulmonem fertur; ibique attenuatur; deinde cum aere una per arteriam venalem ad sinistrum cordis ventriculum defertur; quod nemo hactenus aut animadvertit aut scriptum reliquit; licet maximè et ab omnibus animadvertendum. He afterwards makes a remark, in which Servetus had preceded him, that the size of the pulmonary artery (vena arteriosa) is greater than would be required for the nutrition of the lungs alone. Whether he knew of the passages in Servetus or no, notwithstanding his claim of originality is not perhaps manifest: the coincidence as to the function of the lungs in aerating the blood is remarkable; but, if Columbus had any direct knowledge of the Christianismi Restitutio, he did not choose to follow it in the remarkable discovery that there is no perforation in the septum between the ventricles.
And to Cæsalpin. 15. Cæsalpin, whose versatile genius entered upon every field of research, has, in more than one of his treatises relating to very different topics, and especially in that upon plants, some remarkable passages on the same subject, which approach more nearly than any we have seen to a just notion of the general circulation, and have led several writers to insist on his claim as a prior discoverer to Harvey. Portal admits that this might be regarded as a fair pretension, if he were to judge from such passages; but there are others which contradict this supposition, and show Cæsalpin to have had a confused and imperfect idea of the office of the veins. Sprengel, though at first he seems to incline more towards the pretensions of Cæsalpin, comes ultimately almost to the same conclusion; and giving the reader the words of most importance, leaves him to form his own judgment. The Italians are more confident: Tiraboschi and Corniani, neither of whom are medical authorities, put in an unhesitating claim for Cæsalpin as the discoverer of the circulation of the blood not without unfair reflections on Harvey.[649]
[649] Tiraboschi, x., 49. Corniani, vi., 8. He quotes, on the authority of another Italian writer, il giudizio di que illustri Inglesi, i fratelli Hunter, i quali, esaminato bene il processo di questa causa, si maravigliano della sentenza data in favore del loro concittadino. I must doubt, till more evidence is produced, whether this be true.
The passage in Cæsalpin’s Quæstiones Peripateticæ is certainly the most resembling a statement of the entire truth that can be found in any writer before Harvey. I transcribe it from Dutens’s Origine des Découvertes, vol. ii., p. 23. Idcirco pulmo per venam arteriis similem ex dextro cordis ventriculo fervidum hauriens sanguinem, eumque per anastomosin arteriæ venali reddens, quæ in sinistrum cordis ventriculum tendit, transmisso interim aere frigido per asperæ arteriæ canales, qui juxta arteriam venalem protenduntur, non tamen osculis communicantes, ut putavit Galenus solo, tactu temperat. Huic sanguinis circulationi ex dextro cordis ventriculo per pulmones in sinistrum ejusdem ventriculum optimè respondent ea quæ ex dissectione apparent. Nam duo sunt vasa in dextrum ventriculum desinentia, duo etiam in sinistrum: duorum autem unum intromittit tantum, alterum educit, membranis eo ingenio constitutis. Vas igitur intromittens vena et magna quidem in dextro, quæ cava appellatur; parva autem in sinistro ex pulmone introducens, cujus unica est tunica, ut cæterarum venarum. Vas autem educens arteria est magna quidem in sinistro, quæ aorta appellatur; parva autem in dextro, ad pulmones derivans, cujus similiter duæ sunt tunicæ, ut in cæteris arteriis.
In the treatise De Plantis we have a similar, but shorter passage. Nam in animalibus videmus alimentum per venas duci ad cor tanquam ad officinam caloris insiti, et adepta inibi ultima perfectione, per arterias in universum corpus distribui agente spiritu, qui ex eodem alimento in corde gignitur. I have taken this from the article of Cæsalpin in the Biographie Universelle.