FIX'ED, participle passive Settled; established; firm; fast; stable.

Fixed air, an invisible and permanently elastic fluid, heavier than common air and fatal to animal life, produced from the combustion of carbonaceous bodies, as wood or charcoal, and by artificial processes; called also aerial acid, cretaceous acid, and more generally, carbonic acid.

Fixed bodies, are those which bear a high heat without evaporation or volatilization.

Fixed stars, are such stars as always retain the same apparent position and distance with respect to each other, and are thus distinguished from planets and comets, which are revolving bodies.

Fixed oils, such as are obtained by simple pressure, and are not readily volatilized; so called in distinction from volatile or essential oils.