We use observations from the CASTLES survey of gravitational lenses to study extinction in 23 lens galaxies with 0 < z _ { l } < 1 .
The median differential extinction between lensed images is \Delta E ( \bv ) = 0.05 mag , and the directly measured extinctions agree with the amount needed to explain the differences between the statistics of radio and ( optical ) quasar lens surveys .
We also measure the first extinction laws outside the local universe , including an R _ { V } = 7.2 curve for a molecular cloud at z _ { l } = 0.68 and an R _ { V } = 1.5 curve for the dust in a redshift z _ { l } = 0.96 elliptical galaxy .