I used to work for a photo engraver back in the mid-seventies and we used photo sensitive magnesium plates to expose negatives on and then etch away the unexposed areas around the image or graphic in a nitric acid bath. The plates had to be further machined which produced piles and piles of magnesium shavings. Magnesium has a property that when it comes into contact with water it produces oxygen. I used to think it was great fun to get a steel five gallon bucket packed with shavings good and burning and then hit it with a stream of water from as far back as possible. The effect is astounding, think of a shuttle launch, only with the rockets pointing down. Pretty soon the bucket begins to melt and then the ash starts falling out the smoke that’s reached what seems like hundreds of feet. Cheap fun!