six years after Servetus's ill-fated book was printed, and unquestionably without any knowledge of what was in it; for it does not appear that the discovery by Servetus was known to the world, or produced any influence whatever upon any individual, owing to the character of the work in which it appeared, and to its thorough destruction by fire.
The description which Columbus gives of the circulation of the blood through the lungs is very complete, clear, and concise. "Between the two ventricles is the septum through which it is believed the blood passes from the right to the left; but this is a great mistake, for the blood is carried by the arterial vein into the lungs; thence it passes, with the air, by the venous artery, into the left ventricle of the heart, which no one has yet seen."
His work, "De Re Anatomica," was published in 1559. Columbus died in 1577.
Andreas Cæsalpinus (1519-1603).—This third aspirant for the glory of discovering the pulmonary circulation was born at Arezzo, thirty-eight miles from Florence, Italy, about the year 1519. He was an eminent philosopher, a celebrated botanist, and a distinguished physiologist. He was for many years a professor at Pisa, and subsequently called to Rome, where he also professed, and received the appointment of first physician to Pope Clement VIII. He spent the last years of his life in Rome, where he died February 23, 1603.
The great naturalist Linnæus styled Cæsalpinus the first systematic writer on botany, and followed his classification in many particulars, making it the basis of his own. The history of the physical sciences gives more than one example of the discovery of an important fact by two or more persons, in different places and at different dates, each without previous knowledge of what the other had observed. So do we find it in this instance, Cæsalpinus rediscovered the pulmonary circulation without knowing that both Servetus and Columbus had each previously and independently discovered the same, for he nowhere alludes to them; and he was too noble and honorable a man to bedeck himself with glories not his own.
Moreover, this man was the first who ever employed the felicitous and expressive words, "the circulation of the blood."
"This circulation," said he, "which carries the blood from the right heart through the lung into the left, corresponds perfectly with the disposition of the parts. For each ventricle has two vessels: one by which the blood arrives, and the other by which it departs. The vessel by which the blood arrives at the right ventricle is the vena cava; that by which it leaves is the pulmonary artery. The vessels which pour the blood into the left ventricle are the pulmonary veins; the vessel which affords it exit is the aorta."
No man can describe it more accurately. But Cæsalpinus did not stop here. He was the first and only one before Harvey who gave the