The term pyrotechnics also connotes the skills involved in the making and employment of such illuminative materials. A mixture of saltpeter, sulfur, and charcoal constitutes black powder, used for pyrotechny before it was adapted for military purposes. By the 17th century, elaborate displays of such fireworks accompanied important celebrations. Shortly after 1800 potassium chlorate was substituted for some or all of the potassium nitrate in the explosive mixture, and potassium chlorate or perchlorate is still a key part of most fireworks mixtures. A large number of flammable substances, such as starch , gums, sugar , shellac, and various petroleum derivatives, are frequently used in the mixture in place of charcoal and sulfur.
Color is given to the fire by incorporating compound s of various metals .
Most fireworks are made by incorporating a suitable mixture in a paper case. The most elaborate and spectacular of the fireworks is the skyrocket, a rocket-propelled projectile that explodes high in the air to produce any of several types of display. A red Very shell has the universal significance of danger, and various combinations of red, green, and white shells have various meanings according to standard codes. Flares that are fired into the air and then descend by parachute have also been used in military operations for illumination purposes. The most important military pyrotechnics, however, are smoke and smoke screens.