There are several alchemical texts that refer to tin salt as fuel for "ever-burners" or lamps that always stay lit, although it was proven that these lamps only light when they come in contact with air, so that when a door is opened, the lamp lights at once, giving the illusion that it's been lit ever since it was placed there. So in conclusion, tin salt, if extracted correctly, should in fact, burn when in contact with air.
Here is one text that gives a wonderful explanation of this:
Hydrogen is the element, you are thinking of.
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Several do. The most common of them is phosphorus, but rubidium and cesium also burn on contact to air.
Any highly unstable element, for example white phosphorus.
Hydrogen burns in air to make water
Hydrogen
Titanium
Iodine is the element that undergoes sublimation when exposed to air.
phosphorus
Hydrogen burns in air, usually with a loud pop.
Flammability
Copper (Cu) is the element that turns green when exposed to moist air.
Titanium
oxygen
Iodine is the element that undergoes sublimation when exposed to air.
Water, aka H2O
Phosphorus (15)
phosphorus
Hydrogen burns in air, usually with a loud pop.
Iodine
Flammability
Hydrogen.
The element that burns brilliantly in the air is magnesium. Magnesium is an alkaline Earth metal with the atomic number 12.