1749, February: Madame De Boiseon’s Fiery Death
The account of Madame De Boiseon's death was first recorded by Claude Nicholas Le Cat, a famous surgeon of the 18th century. He did not see the body himself; instead, he received a letter describing the event about two weeks after it occurred in February 1749, and made note of the letter in one of his books. I will sum up the story as he received it.
Madame De Boiseon, 80 years old, was sitting in her chair in front of the fire when her waiting-maid stepped out of the room for a few moments. When she returned, she found Madame De Boiseon on fire. The waiting-maid screamed for help; one of the people who arrived immediately tried to beat out the flames with his hands... only to find that the flames stuck to his hands, as if his hands had been dipped in alcohol or oil on fire.
Next, water was thrown in abundance upon De Boiseon's body, but this seemed to make the fire burn more fiercely. The fire continued to burn until De Boiseon had been reduced to a blackened skeleton sitting in an only minorly scorched chair. Of her body, only one leg and her hands were reasonably intact, all having separated from the torso as it burned.
Madame De Boiseon sat in the same chair in front of the fire daily. There was nothing unusual about the fire in the grate itself, and she had not fallen onto the fire. She was said to have drunk nothing but 'spirits' (alcohol) for several years previous to her death.
The account above, from Le Cat, expressed the idea that De Boiseon had suffered from preternatural combustibility, a theoretical condition in which a human body becomes far more flammable than normal, and can be easily ignited and combusted by exposure to common flame. It was thought that her addiction to alcohol had transferred the combustible properties of the fluid to her body. It's not clear from the account I have if Le Cat himself believed this, or if he was simply repeating a theory from the letter he was writing about.
Joe Nickell, in his book Secrets of the Supernatural, proposed that De Boison was ignited accidentally by the fire in the grate, and was too intoxicated or disabled to save herself; in short, he felt she was an example of the "wick effect," a situation in which a person's clothes act like a candlewick by sucking up and burning the melting body fat of the victim. But Nickell doesn't mention why De Boiseon's chair was left relatively unburned, and why water would make her body burn more; if these are true and correct details, then they point to a fire that behaves in a paranormal fashion.