Not long ago I posted Calvin and Servetus Revisited. In that entry I included a 20 minute section on Calvin and Servetus that Dr. White did on the Dividing Line. During his explanation, he mentioned that Servetus has been credited with describing the circulatory system and that he hadn’t had a chance to check the accuracy of this claim.
I think I’ve found the source. I picked up a very interesting book recently entitled Out Of The Flames (New York: Broadway Books, 2002) by Lawrence and Nancy Goldstone. The book is entirely about Michael Servetus and his book the Christianismi Restitutio. This book by Servetus was that text sent to Calvin as an attack on the Institutes. According to the authors, the Christianismi Restitutio became one of the rarest books in the world. They tell quite a fascinating tale of how this rare book survived through the centuries.
It appears the claim about the circulatory system comes from the Christianismi Restitutio. The following quote appears on page 171 in Book V:
The substantial generation of the vital spirit is composed of a very subtle blood nourished by inspired air…It is generated in the lungs from a mixture of inspired air with elaborated, subtle blood which the right ventricle of the heart communicates with the left. However, this communication is not made through the middle wall of the heart as is commonly believed, but by a very ingenious arrangement, the subtle blood is urged forward by a long course through the lungs; it is elaborated by the lungs, becomes reddish yellow and is poured from the pulmonary artery into the pulmonary vein. Then in the pulmonary vein it is mixed with inspired air through the expiration it is cleansed of its sooty vapors. Thus finally the whole mixture, suitably prepared for the production of the vital spirit, is drawn onward from the left ventricle of the heart by diastole. [Out Of The Flames, pp. 197-198].
The authors add, “This was a description of pulmonary circulation, perhaps the single most important statement about the workings of the human body in fifteen hundred years.” The Goldstone’s also tell quite an interesting historical story of how this claim from Servetus was unearthed, given the fact the copies of the Christianismi Restitutio were not thought to exist. It wasn’t until 1694 that someone actually mentioned the claim in print. What first began as hearsay later was documented when an copy of the Christianismi Restitutio was discovered, and it turned out, according to the authors, to be the very copy of the text used by Germain Colladon during the trial of Servetus.