  This paper presents the nuclide cross sections and the longitudinal velocity
distributions of residues produced in the reactions of 136Xe and 124Xe at 1 A
GeV in a lead target, measured at the high-resolution magnetic spectrometer,
the Fragment Separator (FRS) of GSI. The data cover a broad range of isotopes
of the elements between Z = 3 and Z = 56 for 136Xe and between Z = 5 and Z = 55
for 124Xe, reaching down to cross sections of a few microbarns. The velocity
distributions exhibit a Gaussian shape for masses above A = 20, while more
complex behaviour is observed for lighter masses. The isotopic distributions
for both reactions preserve a memory on the projectile N/Z ratio over the whole
residue mass range.
