fixed air

Fixed \Fixed\ (f[i^]kst), a.
   1. Securely placed or fastened; settled; established; firm;
      imovable; unalterable.
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   2. (Chem.) Stable; non-volatile.
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   {Fixed air} (Old Chem.), carbonic acid or carbon dioxide; --
      so called by Dr. Black because it can be absorbed or fixed
      by strong bases. See {Carbonic acid}, under {Carbonic}.

   {Fixed alkali} (Old Chem.), a non-volatile base, as soda, or
      potash, in distinction from the volatile alkali ammonia.
      

   {Fixed ammunition} (Mil.), a projectile and powder inclosed
      together in a case ready for loading.

   {Fixed battery} (Mil.), a battery which contains heavy guns
      and mortars intended to remain stationary; --
      distinguished from movable battery.

   {Fixed bodies}, those which can not be volatilized or
      separated by a common menstruum, without great difficulty,
      as gold, platinum, lime, etc.

   {Fixed capital}. See the Note under {Capital}, n., 4.

   {Fixed fact}, a well established fact. [Colloq.]

   {Fixed light}, one which emits constant beams; --
      distinguished from a flashing, revolving, or intermittent
      light.

   {Fixed oils} (Chem.), non-volatile, oily substances, as
      stearine and olein, which leave a permanent greasy stain,
      and which can not be distilled unchanged; -- distinguished
      from volatile or {essential oils}.

   {Fixed pivot} (Mil.), the fixed point about which any line of
      troops wheels.

   {Fixed stars} (Astron.), such stars as always retain nearly
      the same apparent position and distance with respect to
      each other, thus distinguished from planets and comets.
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