ACHROMATIC a.
Uncolored; not absorbing color from a fluid; -- said of tissue. Achromatic lens (Opt.), a lens composed usually of two separate lenses, a convex and concave, of substances having different refractive and dispersive powers, as crown and flint glass, with the curvatures so adjusted that the chromatic aberration produced…
ACOUSTIC a.
Pertaining to the sense of hearing, the organs of hearing, or the science of sounds; auditory. Acoustic duct, the auditory duct, or external passage of the ear. -- Acoustic telegraph, a telegraph making audible signals; a telephone. -- Acoustic vessels, brazen tubes or vessels, shaped like a bell, used in ancient the…