Abstract: An apparatus for introducing tubes automatically into a gas pathway between a gas source and a gas chromatograph when the apparatus is in use, the apparatus comprisinga gravity feed magazine for storing tubes,means for introducing a tube horizontally from the magazine to a gas pathway whereby, when the apparatus is in use, gas is introduced through a first pipe from a gas source to one end of the tube and is passed through the tube to a second pipe for introducing the gas into a gas chromatograph, one end of the tube and one end of the first pipe abutting opposite sides of a first resilient ring and the other end of the tube and one end of the second pipe abutting opposite sides of a second resilient ring the rings sealing the first pipe, tube and second pipe in the gas pathway while allowing gas to flow from the first pipe to the tube and from the tube to the second pipe.means for heating the tube when in the gas pathway andmeans for ejecting the tube from the pathway.