an adiabatic compression of a gas increases its internal energy, or temperature. students readily accept this fact but few realize how great the temperature increase can be. the fire syringe provides a good pedagogical demonstration to show the elevation in temperature upon a very rapid (adiabatic) compression of air. the syringe consists of a heavy-walled glass tube, closed at one end and fitted with a piston at the other. cotton or tissue paper, placed at the bottom of the tube, ignites in a flash when the piston rapidly compresses the confined air. in this device the temperature approaches 800k as is estimated from the equation giving the relation between volume and temperature in the adiabatic compression of an ideal gas. class demonstrations with the commercial fire syringe have been unsatisfactory due to the fact that the piston must be depressed several times before the flash is observed. for this reason a search was undertaken to find a material with a lower ignition temperature than that of the cotton or tissue paper suggested by the vendor. since book matches readily ignite when stroked on a special abrasive surface, a match head was tried as the combustible material. success accompanied the first down-stroke of the piston. this suggested an investigation of a variety of book matches to ascertain which would ignite at the lowest temperature matches made by seven manufacturers were tested and all were found to have ignition temperatures in the range 509 to 522k. tissue paper ignited at 630k and cotton required a temperature of 680k. 'strike anywhere' matches were t