Humans breathe air. In contrast, the gods of ancient Greek mythology inspired aither, aether, or ether. Rather than the transparent gas inhaled by mortals, the deities breathed the blue gas found on mountain tops and in the heavens—all that lofty atmosphere above ground but beneath the solid dome of the Sky (Ouranos, Latinized as Uranus). Unlike earthly elements, which moved linearly, Aither circulated around heavenly bodies in circular orbits within ethereal spheres. In his Cratylus, Plato suggests that aither derives from aei thein (“always running”). Aither also serves as a backdrop for parts of Giulio Romano’s c.1533 trompe l’oeil frescoed ceiling in the Chamber of the Giants (a portion above), Palazzo del Te, Mantua, Italy. Volatile and intoxicating, our earthly anodyne, ether, may have seemed a gift from the gods. Alas, the only “blues” ether elicited in 19th-century mortals arose from recreational overindulgence. (Copyright © the American Society of Anesthesiologists’ Wood Library-Museum of Anesthesiology. www.woodlibrarymuseum.org)