  We report the first observation of the annihilation of positronium from the
2S state. Positronium (Ps) is excited with a two-photon transition from the 1S
to the 2S state where its lifetime is increased by a factor of eight compared
to the ground state due to the decrease in the overlap of the positron electron
wavefunction. The yield of delayed annihilation photons detected as a function
of laser frequency is used as a new method of detecting laser-excited Ps in the
2S state. This can be considered the first step towards a new high precision
measurement of the 1S-2S Ps line.
