This is real. I mean not all soldiers, but:
“As the sun went down after the 1862 Battle of Shiloh during the Civil War, some soldiers noticed that their wounds were glowing blue. Many men waited on the rainy, muddy Tennessee battlefield for two days that April, until medics could treat them. Once they were taken to field hospitals, the troops with glowing wounds were more likely to survive their injuries — and to get better faster. The mysterious blue light was dubbed “Angel’s Glow.”
Honestly, with the information available at the time, it would be weirder NOT to get religion after that. The cause of it was a bioluminescent bacteria called Photorhabdus luminescens. It has a symbiotic relationship with tiny nematode worms. The nematodes are parasites. So what happens is, the nematodes go into a host insect larva, and vomit up their P. luminescens – which are powerfully antibacterial and antimicrobial. So the nematode and the P. luminescens get to eat the larva with no competition from other organisms. When they’re done eating, the nematode swallows the P. luminescens again. The bacteria glows blue, attracting insects, making it easy for the nematodes to find a new host. P. luminescens lives in the soil when its not inside a nematode, and was presumably in the mud of the battlefield .
You probably know enough of the 1800s to understand what a drastic effect an antibacterial substance would have had on wounded soldiers’ mortality rate. So why wasn’t this happening constantly? P. luminescens can’t survive at human body temperature. It’s too hot for them. The soldiers at the Battle of Shiloh had been left in the rain for two days, and had hypothermia. Source.
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