Surely such an idea must have originated in an era where, at the very least, revolvers were no longer considered cutting-edge technology, right? Wrong: Back in 1898, Edison's Conquest of Mars described the Martians as carrying "hand engines, capable of launching bolts of death of the same character as those which emanated from the knobs of their larger machines." So, rather than coming up with new weapons, Serviss had simply taken the giant mounted heat cannons used by the aliens in The War of the Worlds and made them smaller, accidentally inventing one of the most classic staples of science fiction.
"Making a whole new weapon sounds hard, I'll just revolutionize the genre instead."
In Edison's Conquest, the effect of these rays can reduce the humans to "heaps of cinder" -- but what about flat-out disintegration? This book has that, too ... on the human side. Early on, Edison invents a little portable device with the power to break molecular structures and disperse the atoms of any given object, leaving only an existentially haunting mist behind. The characters even refer to it as a "disintegrator," despite the device being described as something resembling a pocket mirror.
"Hey, does it say 'Patented by Nikola Tesla' on the side?"
Before leaving for Mars, Edison demonstrates the weapon by aiming it at a crow and disintegrating its feathers while leaving the bird unharmed. He of course then kills the bird anyway because, as we never get tired of mentioning, Edison was kind of a dick.
"Hahaha, fuck you, bird. Hahahahaha."