438. From Mirrors to Incandescent Bulbs: The 19th- Century Leap

By the mid-19th century, improvements in illumination and optics transformed endoscopy from a theoretical idea into a practical clinical tool, culminating in Antoine Jean Desormeaux's work in Paris in 1853. Building on Bozzini's Lichtleiter and frustrated by diagnostic limits of palpation, Desormeaux replaced candlelight with a brighter, controllable source known as the gazogène.