Science & Technology

This Is Why Some Civil War Soldiers' Wounds Began to Glow

Imagine you are a Civil War soldier with a mid-19th-century layman's understanding of medicine. Good news: You helped drive the Confederates back and survived the Battle of Shiloh. Bad news: You're wounded, and you've been waiting for a medic for two days on a rainy battlefield. Worse news: To your horror, that wound has started to ... glow. Never mind that archaic understanding of medicine — we're still freaked out 156 years later.

In the Glow of an Angel

The Battle of Shiloh was one of the first major battles of the American Civil War, and one of the first bloodbaths as well. Although the Union was victorious, both sides suffered heavy losses, and neither was truly prepared for the scope of the conflict. All told, the Battle of Shiloh left more than 3,000 dead and 16,000 wounded, and like many Civil War battles, the deadliest risk came after the bullets stopped flying and the wounds started festering. To make matters worse, the wounded that were unable to carry themselves from the fray were left to suffer for two days in the mud and the rain before medical help (such as it was at the time) arrived. That can't be good for preventing infection. Fortunately, those soldiers had angels looking out for them.

At least, that's what it looked like. In an astonishing, and frankly spooky, turn of events, as night fell, many of those wounded soldiers began to see a strange glow emanating from their wounds. They called it "Angel's Glow" and it lived up to its nickname. When they were eventually recovered and moved to the field hospital, the soldiers whose wounds had been so blessed ended up recovering better and faster, with cleaner wounds and a better survival rate than the un-glowing. This really would sound downright impossible if it weren't for the fact that it's so well documented.

When P. Luminescens Comes Marching Home

In 2001, an answer finally came to the supernatural mystery, and it came from an unlikely source: a 17-year-old high school student. Bill Martin was visiting the battlefield of Shiloh with his mother Phyllis Martin, a microbiologist at the USDA Agricultural Research Service. Hearing the story of the glowing soldiers, he thought about another story his mother had told him: the story of the bioluminescent bacteria Photorhabdus luminescens, which glows with a pale blue light. He and his friend John Curtis decided to conduct an experiment to find out if that little critter could be the culprit.

The students found that P. luminescens would indeed have been well-suited to surviving in the mud at Shiloh, but that the inside of the human body was probably too hot. However, they realized that since the soldiers would have been experiencing the cool Tennessee nights from the bottom of a mud puddle in the pouring rain, they may well have been experiencing hypothermia, which would lower their temperatures enough for the bacteria to thrive.

P. luminescens normally survives by hitching a ride on a parasitic nematode and chowing down on the insects that nematode infects. It's a complicated and somewhat nauseating life cycle that starts up again by creating a glowing insect corpse that attracts more insects to infect. A crucial part of that process is when P. luminescens makes room for itself and for its parasitic host by cleaning up all of the other bacteria in its way. If this glowing duo happened to find its way into a human wound instead of the insects it normally hunts, it'd clean that wound right up. And since it's not especially infectious to humans (although it certainly can be), P. luminescens is usually no match for our immune systems. There you have it: We wouldn't recommend introducing a new parasite to fight your infections today, but as Civil War medicine goes, it's certainly preferable to a field amputation.

Get stories like this one in your inbox or your headphones: sign up for our daily email and subscribe to the Curiosity Daily podcast.

There might not be any images of the glowing soldiers on that bizarre battlefield, but the American Civil War is still one of the first wars to be documented with the exactness of photography. Flip through "The Civil War: A Visual History" (put out by the Smithsonian) to see exactly what the brave soldiers of the Union went through. We handpick reading recommendations we think you may like. If you choose to make a purchase through that link, Curiosity will get a share of the sale.

Written by Reuben Westmaas June 29, 2018

Curiosity uses cookies to improve site performance, for analytics and for advertising. By continuing to use our site, you accept our use of cookies, our Privacy Policy and Terms of Use.