Chicago, Sept. 8, 1904.
To the Editor:
—An ideal light for eye, ear, nose and throat work is made by dipping a suitably sized segment of the frosted portion (sand-blast formation) of a 24-candle-power spiral electric lamp in hydrofluoric acid. After dipping it in the acid for a few seconds, wash it off in water, dry and test its translucency. Each application of the acid eats the rough points of glass, leaving it thinner, smoother and more nearly transparent. Continue this until light of desired intensity is obtained, yet stopping short of the point where the reflection of the coil can be produced by a forehead mirror held at its focal distance from a smooth surface as well as from the lamp. A uniform and intense white light is obtained.I have suggested to a bulb maker that where an asbestos chimney is needed a plain bulb small enough to