Mary Ellen Thomas, age 12, Ottawa, Ontario
How do fireworks get their colors?
The basic recipe for making fireworks is black gunpowder. Color is added with a pinch of salts but not the common salt which adds flavor to a hamburger. The dazzling sparks from a Roman candle are colored by complex chemicals called metallic salts, special compounds prepared from metals.
Then a cash of sodium salts is added to the basic recipe, the firework goes off in a shower of primrose yellow sparks. Then strontium salts are added the color is rosy crimson. Barium salts give a lovely green display and a touch of copper salts lights up the sparks with green or brilliant blue, Magnesium or, aluminum salts are added to give a silvery white effect to the fireworks. Just a pinch of these salts is needed to give distinctive colors to the displays but usually other chemicals are adds to sharpen the colors. Calomel or a substance called hexachlorobenzine add the dash of spice which heightens and brightens the colors,
Black gunpowder was invented by the Chinese thousands of years ago and we did not invent the guns to go with it until much, much, later. The Chinese merely wanted to welcome the New Year with a bang, The first firecracker probably went off on the floor with no more than a loud pop ‑ but the Chinese vrere delighted with it and set about improving it,
They experimented with saltpeter, sulphur and charcoal until they got a mixture that was ,just right. We have no records of these experiments, but we are sure there were many casualties, Whiskers were singed, fin.7ers mere burned and there were serious tragedies ‑ for gunpowder is a very dangerous explosive, That is why young people do not set off firecrackers. They leave this to a trained adult who knows how to find the right spot for a display and do the job safely.
As the ancient mixture improved, so did the firecrakers, In order to be safe the pellets enters encased the gunpowder in a tube and lit it from a fuse .. which gave them time to get out of the way before the explosion. They saw that a tube of gunpowder, lit from one end, tends to launch itself up in the air. Actually, a stream of expanding hot air from the rear forces the tube to rise, Without knowing it, these happy experimenters invented the jet propelled rocket lone before anyone dreamed of flying an airplane.
In tame they learned to control the sparks from a rocket by wadding, the gunpowder in gum. We use the same method in a modern Roman candle. The rocket tube is pocked with. gummy balls of gunpowder, each tinted with its own colored salts, and the balls are separated by a slow burning material. That way we get a controlled shower of colored sparks which gives the people time to say ooh and ah,