Anatomical Observations on the Lungs

Nor is there any doubt that within the mass of the blood there are parts prone to easy union, which reach such solidity that they sometimes rival the hardness of a stone. Evidence of this may be found in the red part of the blood, which, when separated from the serum The clear, yellowish fluid component of blood that remains after clotting., dries out so much that it takes on the appearance of a stone; although it remains crumbly, it breaks into fragments of a specific shape. Likewise, a portion of the serous substance, when thickened by the gentle heat of a fire, becomes bony and transparent through a stronger binding over time.

Therefore, these particles, when properly mixed together, create a certain fluid as a whole. First, the serum is made flowable by a mixture of an aqueous substance; the existence of this watery substance is shown by the perceptible evaporation rising from a pan while the serum thickens. Even more clearly, a certain liquid with the smell and taste of urine original: "vrinam reprehensentans"; likely referring to urea or other salts found in the blood. is separated from the blood serum by means of an alembic An early chemical apparatus used for distillation, consisting of two retorts connected by a tube.. This liquid usually maintains almost the same volume as the thickened serum. Then there is bile and various salts, which are extracted in abundance from the watery serum; for when these are dissolved and properly mixed with the serum, they cause a greater dissolution and flowability of the parts.

I It is from the serous, or this "white" part, that the flowability of the other part—namely, the red—arises. We see this clearly from the opposite case in blood drawn from a cut vein: for once the tiny red particles are separated from the mixture—perhaps stirred into motion by hot particles escaping outward—they unite with their own kind, and the serous substance is squeezed out on all sides and separated.

This same phenomenon is observed in living beings where scirrhous tumors original: "scirrosi tumores"; hard, fibrous, and often cancerous growths. and black mucus accumulate; the common people seem to recognize the origin of these in melancholy original: "melancholia" or "black bile" original: "atra bile"; in humoral theory, an excess of black bile was thought to cause both physical tumors and emotional depression.. All this is confirmed by a common experiment: for women, so that blood coming from a still-living animal does not divide into its parts by thickening, are accustomed to stir and agitate it with their fingers or a stick, specifically so that this strong mixture of white and red might be preserved.

Therefore, so that this mixing might succeed perfectly—and that the smallest amount of white might intervene and touch the smallest amount of red, and that the mass of the blood might be restored through a stable mixture—nature has fashioned the lungs. To these, they [bring] light The text ends mid-sentence; the catchword "ferunt" suggests the next page begins with "bring light" or "reveal."