4B70.10: Fire Syringe

Description: This demonstration shows the relationship between Pressure, Volume, and Temperature in an adiabatic compression.

Equipment: Setup Procedure:
  1. Oil the three rubber washers on each fire syringe and wipe it off with a tissue.
  2. Break off 2 small pieces of gun cotton, about the size of a grain or rice or a BB bullet.
  3. Place each in the bottom of a fire syringe.
Demonstration Procedure:
  1. It is highly recommended that professors try this out before class to get a feel of how much pressure to use.
  2. Stand the fire syringe up vertical on the table and insert the metal stopper.
  3. When ready, push down the fire syringe with a good amount of pressure.
  4. As you push down, hold the metal stopper on the recoil back or it will pop out.
  5. The gun cotton should ignite. This happens because the volume quickly decreases, and the temperature goes up. Enough to ignite the gun cotton.