Anatomical Observations on the Lungs

...fulfill the desire, and you yourself add credit to the truth, for while in Rome you marveled that from the trunk of a Massilian apple original: "massilici mali"; likely referring to a pomegranate or a specific variety of citrus common in Roman gardens a vine and jasmine had come forth. These clever feats were achieved by the one who cultivated the gardens, by grafting a light shoot into larger branches; he taught the trees not to resist the production of diverse fruits. Indeed, Virgil sang aptly on this matter in his Georgics:

original: "aliena ex arbore germen / Includunt, udoq́; docent inolescere libro." From Virgil’s Georgics, Book 2, lines 76–77, describing the process of inoculation or budding.

You reveal the secret of this wonderful effect through your own method of philosophizing. For we must judge that the acidic juice of the Massilian apple sweetens into the nature of pure wine only insofar as the particles of that juice—though they flow successfully through the thin passages of its own trunk—cannot enter the continuous tubes of the vine in the same way. Hence, driven by their own motion and the impulse of the fluids following behind them, they are torn apart and broken out of their usual order. It is necessary that they adapt themselves to the shape of the newly introduced passage and take on a new nature, by which both the vine and the jasmine are produced.

Nature accomplishes a similar mode of operation in the lungs. The blood returns from the circuit of the body deprived of its nourishing particles and in a disturbed state; to this, a new fluid This refers to chyle, the milky fluid containing fats and proteins from digestion, which enters the bloodstream near the heart. is added from the subclavian veina large vein in the upper chest that serves as the entry point for lymphatic fluid into the circulatory system, to be perfected by a further action of nature. Therefore, so that this fluid may be arranged and prepared into the nature of particles of flesh, bone, nerve, and so on, it enters the myriads of pulmonary vessels. There, it is drawn out as if into diverse, tiny threads, and thus a new shape, position, and motion are imparted to the blood particles, through which flesh, bones, and spiritsin 17th-century physiology, "animal spirits" were thought to be refined fluids responsible for nerve sensation and movement can be formed. The truth of your statement is further confirmed by the similar structure of the seminal vesselsthe vessels of the reproductive system, as if the nutrition of a living thing were a kind of regenerationMalpighi suggests that daily nutrition is essentially the same process as the original formation or "generation" of the body of the same.

I have gathered these few thoughts into a letter so that I might expand upon what has already been discovered about the lungs. If I have gained any ground, I owe this entire addition to my observations to the frog The transparent lungs of frogs allowed Malpighi to see capillaries for the first time, proving that blood circulates through closed vessels rather than pooling in tissue.. You grant value and dignity to these matters by your authority and discovery. Meanwhile, philosophize joyfully, and continue to make me entirely happy with these minimal thoughts of mine...