HERO’S BOOK ON PNEUMATICS

Indeed, regarding medical vessels original: "medica quae ex uitro constant." Hero refers to glass instruments used by physicians in antiquity, likely pipettes or "dipping tubes." that are made of glass and have narrow mouths: when people wish to fill them with liquid, they suck out the air contained within them with their mouths. Then, blocking the opening with a finger, they turn the vessel into the liquid. When the finger is released, water is drawn into the emptied space exinanitum, and thus the liquid itself is carried upward against its natural tendency In ancient physics, the "natural" motion of water was downward; "against nature" refers to the suction force overcoming gravity..

And what occurs regarding the cupping glass cucurbitula The "cucurbitula" or cupping glass was a bell-shaped vessel used in bloodletting. Fire was placed inside to create a vacuum before it was applied to the skin. is certainly not foreign to the things we have described. For when these are applied to the body, they not only do not fall off—even though they have a noticeable weight—but they also draw the adjacent matter through the pores original: "raritates." Literally the "rarity" or thinness of the body's surface, referring to pores. of the skin for the same reason. For the fire placed inside consumes original: "corrumpit." In this context, Hero means the fire breaks down or transforms the air, not "corrupts" in a moral sense. and thins the air contained within the glass, just as other bodies are consumed by fire and changed into thinner substances—I mean air, water, and earth.

That bodies are indeed consumed is manifest from the coals left behind. For although these coals preserve the same volume molem they had at the beginning before combustion, or perhaps a little less, they differ greatly in weight. Those parts of the bodies that are consumed pass through smoke into fiery, airy, and earthy substances. For the parts that are thinner [are carried off] in smo-