{Compound microscope}, an instrument consisting of a
combination of lenses such that the image formed by the
lens or set of lenses nearest the object (called the
objective) is magnified by another lens called the ocular
or eyepiece.
{Oxyhydrogen microscope}, and {Solar microscope}. See under
{Oxyhydrogen}, and {Solar}.
{Simple, or Single}, {microscope}, a single convex lens used
to magnify objects placed in its focus.
2. (Biol.) 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 by the one is
corrected by other, and light emerges from the compound
lens undecomposed.
{Achromatic prism}. See {Prism}.
{Achromatic telescope}, or {microscope}, one in which the
chromatic aberration is corrected, usually by means of a
compound or achromatic object glass, and which gives
images free from extraneous color.