資料來源 : Webster's Revised Unabridged Dictionary (1913)

   Note: Although a gas, hydrogen is chemically similar to the
         metals in its nature, having the properties of a weak
         base. It is, in all acids, the base which is replaced
         by metals and basic radicals to form salts. Like all
         other gases, it is condensed by great cold and pressure
         to a liquid which freezes and solidifies by its own
         evaporation. It is absorbed in large quantities by
         certain metals (esp. palladium), forming alloy-like
         compounds; hence, in view of quasi-metallic nature, it
         is sometimes called {hydrogenium}. It is the typical
         reducing agent, as opposed to oxidizers, as oxygen,
         chlorine, etc.

   {Bicarbureted hydrogen}, an old name for ethylene.

   {Carbureted hydrogen gas}. See under {Carbureted}.

   {Hydrogen dioxide}, a thick, colorless liquid, {H2O2},
      resembling water, but having a bitter, sour taste,
      produced by the action of acids on barium peroxide. It
      decomposes into water and oxygen, and is manufactured in
      large quantities for an oxidizing and bleaching agent.
      Called also {oxygenated water}.