1654 (pre): French Woman’s Fiery Stomach
Sometimes previous to 1654, when Thomas Bartholin published an account of the event, a French woman died in the vicinity of Lyon when a flame burst forth from her stomach, but was quickly extinguished. Doctors that examined her corpse were of the opinion that the fire had been caused either by an excess of alcoholic drink, or by overuse of antidote for poisonous bites.
As it turns out, Bartholin published two accounts of this events, one in 1654 and one in 1657; and while the 1654 account is not too clear on the matter, the 1657 account states that the flames occurred after the woman's death. The fire occured when doctors were examining her corpse, and it's unstated as to whether or not they occurred on their own or if they were sparked by the doctors' activity somehow. The second possibility seems likely, as Bartholin states that huge flames were seen to burst out of her stomach, which then quickly extinguished themselves... which sounds like the doctors had cut her stomach open and somehow ignited the gases that rushed out. After this surprising flame, it was noted that the exposed internal cavity had been effected. The fire probably used up all the oxygen available within the cavity, and then extinguished itself.
This report makes sense for the time; medically speaking, it had been discovered that the gases in stomachs were flammable, so many doctors were watching for instances suggestive of said gases igniting. Bartholin mentions alcohol as a possible cause for the matter, which also follows a point of belief at the time... the thought was that, since alcohol was flammable itself, that it could ignite within a person's body, or make a person's body more flammable unto itself.
One intriguing question about the matter, though, is the other theory that Bartholin put forward: that the woman's overuse of 'theriaces' may have caused the incident. Since theriaces were a medicine meant to fight poison and poisonous bites, it implies there was other chemicals in the woman's body at death, which could have added to the effect.