ANGEL’S GLOW
Why injured Civil War soldiers glowed with a pale-blue light that seemed to heal their wounds
Avital victory for Union forces in the American Civil War, the 1862 Battle of Shiloh was fought in dreadful conditions. Bodies strew the battlefield, with field hospitals overrun on both sides. At night, when soldiers looked out at their fallen comrades and heard their cries of agony, a blue glow discharged from some of the troops. It was later discovered that those who had emitted the light were more likely to recover and heal quicker. They gave it the nickname ‘Angel’s Glow’.
It wasn’t until almost 150 years later that a theory was put forward as to why this happened. William Martin may only have been 17 years old, but he and high-school friend Jonathan Curtis discovered why this ghostly pale-blue light helped clear wounds. The theory was that luminous parasitic roundworms in the ground entered the wounds and killed the bacteria that infected them. The roundworms, or nematodes, produced antibiotics that helped sanitise the injuries while consuming the microorganisms themselves. The bacteria produced by the nematodes was Photorhabdus luminescens, which as the name implies emits a glow. Only the soldiers that had hypothermia had Angel’s Glow. This was because P. luminescens normally feasts on the bodies of cold-blooded insects that have a much lower body temperature. When the injured soldiers were warmed up in the hospitals, the bacteria died and the glowing stopped. But by then the wounded had a better chance to recover with fewer microbes infecting their injuries. The duo scooped a national science prize for their efforts and the phenomenon that amazed soldiers in 1862 was finally understood.