  We measure and analyze the isotope shifts the multiplet of transitions
between the metastable a$^5$F and excited y$^5$G$^\circ$ terms of neutral
titanium by probing a titanium vapor in a hollow cathode lamp using saturated
absorption spectroscopy. We resolve the five $J\to J+1$ and the four $J\to J$
transitions within the multiplet for each of the the three $I=0$ stable
isotopes ($^{46}$Ti, $^{48}$Ti, and $^{50}$Ti). The isotope shifts on these
transitions allow us to determine the isotope-dependent variation in the
fine-structure splitting of the a$^5$F and y$^5$G$^\circ$ levels themselves.
Combined with existing knowledge of the nuclear charge radii of titanium
nuclei, we derive the specific mass and field shifts, which arise from
correlated electronic motion and electronic density at the nucleus
respectively, and further observe a strong $J$-dependent variation in each. Our
results yield insight into the electronic and nuclear structure of transition
metal atoms like titanium, and also characterize optical transitions that may
allow for optical manipulation of ultracold gases of transition metal species.
