In 1892 Welch and Nuttall described a gas-forming bacillus (bacillus aerogenous capsulatus), which they obtained from emphysematous tissues and blood of a man who died of aneurysm of the aorta. Gas bubbles were present in the internal organs, especially in the heart's flesh, liver, spleen, and kidneys. This gas burned with a pale bluish, almost colorless flame, ignition causing a slight detonation. Microscopic examination showed masses of bacilli, some degenerative changes, including disappearance of the nuclei of the cells of some of the organs, especially in the neighborhood of the gas cavities, in the walls of which the bacilli were often quite numerous.
Since their description a number of interesting reports, bearing upon the action of this organism in the living as well as in the dead tissues, have appeared (Dunham, Norris and others.) In their original paper Welch and Nuttall suggested that many of the deaths attributed to air