  The lifetime of the $E^3\Pi_g(v=3)$ state of molecular iodine was measured in
the gas phase at room temperature. The $E^3\Pi_g$ state was selectively
populated by two sequential nanosecond pulse laser excitation. Resolved
molecular fluorescence for the $B^3\Pi_u^+\leftarrow E^3\Pi_g$ was analyzed and
the lifetime of the $E(v=3)$ state, measured using a time-correlated single
photon counting technique, is to be $\tau=21 (2)$ ns.
