Feb. 25, 1946

Within the box raged a miniature storm of aluminum powder, churned bycompressed air. With each breath the miners inhaled about five milliontiny aluminum particles. The doctors’ theory: aluminum powder forms acoating around silica powder in the air sacs, prevents formation oflung-eating silicic acid.

Miners liked the treatment so well that some drove 40 miles a day to getit. They reported immediate relief from the dry, hacking coughcharacteristic of silicosis. But whether aluminum dust will vanquishsilica dust permanently, neither doctor nor miner could yet say. Norhad they yet found out whether it prevents tuberculosis, which oftenends the silicosis sufferer’s life.