  We homogeneously analyzed the \chandra\ X-ray observations of 10
gravitational lenses, HE 0047-1756, QJ 0158-4325, SDSS 0246-0805, HE 0435-1223,
SDSS 0924+0219, SDSS 1004+4112, HE 1104-1805, PG 1115+080, Q 1355-2257, and Q
2237+0305, to measure the differential X-ray absorption between images, the
metallicity, and the dust-to-gas ratio of the lens galaxies. We detected
differential absorption in all lenses except SDSS 0924+0219 and HE 1104-1805.
This doubles the sample of dust-to-gas ratio measurements in cosmologically
distant lens galaxies. We successfully measured the gas phase metallicity of
three lenses, Q 2237+0305, SDSS 1004+4112, and B 1152+199 from the X-ray
spectra. Our results suggest a linear correlation between metallicity and
dust-to-gas ratio (i.e., a constant metal-to-dust ratio), consistent with what
is found for nearby galaxies. We obtain an average dust-to-gas ratio
$E(B-V)/N_H=1.17^{+0.41}_{-0.31} \times 10^{-22}\rm mag\,cm^2\,atom^{-1}$ in
the lens galaxies, with an intrinsic scatter of $\rm0.3\,dex$. Combining these
results with data from GRB afterglows and quasar foreground absorbers, we found
a mean dust-to-gas ratio $\mdtg,$ now significantly lower than the average
Galactic value, $1.7\,\times 10^{-22}\,\rm mag\, cm^{2}\, atoms^{-1}.$ This
suggests evolution of dust-to-gas ratios with redshift and lower average
metallicities for the higher redshift galaxies, consistent with current metal
and dust evolution models of interstellar medium. The slow evolution in the
metal-to-dust ratio with redshift implies very rapid dust formation in high
redshift ($z>2$) galaxies.
