  We used the monochromatic soft-x-ray beamline P04 at the
synchrotron-radiation facility PETRA III to resonantly excite the strongest
$2p-3d$ transitions in neon-like Ni XIX ions, $[2p^6]_{J=0} \rightarrow
[(2p^5)_{1/2}\,3d_{3/2}]_{J=1}$ and $[2p^6]_{J=0} \rightarrow
[(2p^5)_{3/2}\,3d_{5/2}]_{J=1}$, respectively dubbed 3C and 3D, achieving a
resolving power of 15\,000 and signal-to-background ratio of 30. We obtain
their natural linewidths, with an accuracy of better than 10\%, as well as the
oscillator-strength ratio $f(3C)/f(3D)$ = 2.51(11) from analysis of the
resonant fluorescence spectra. These results agree with those of previous
experiments, earlier predictions, and our own advanced calculations.
