Source : Webster's Revised Unabridged Dictionary (1913)

Sponge \Sponge\, n. [OF. esponge, F. ['e]ponge, L. spongia, Gr.
   ?, ?. Cf. {Fungus}, {Spunk}.] [Formerly written also
   {spunge}.]
   1. (Zo["o]l.) Any one of numerous species of Spongi[ae], or
      Porifera. See Illust. and Note under {Spongi[ae]}.

   2. The elastic fibrous skeleton of many species of horny
      Spongi[ae] (keratosa), used for many purposes, especially
      the varieties of the genus {Spongia}. The most valuable
      sponges are found in the Mediterranean and the Red Sea,
      and on the coasts of Florida and the West Indies.

   3. Fig.: One who lives upon others; a pertinaceous and
      indolent dependent; a parasite; a sponger.

   4. Any spongelike substance. Specifically:
      (a) Dough before it is kneaded and formed into loaves, and
          after it is converted into a light, spongy mass by the
          agency of the yeast or leaven.
      (b) Iron from the puddling furnace, in a pasty condition.
      (c) Iron ore, in masses, reduced but not melted or worked.

   5. (Gun.) A mop for cleaning the bore of a cannon after a
      discharge. It consists of a cylinder of wood, covered with
      sheepskin with the wool on, or cloth with a heavy looped
      nap, and having a handle, or staff.

   6. (Far.) The extremity, or point, of a horseshoe, answering
      to the heel.

   {Bath sponge}, any one of several varieties of coarse
      commercial sponges, especially {Spongia equina}.

   {Cup sponge}, a toilet sponge growing in a cup-shaped form.
      

   {Glass sponge}. See {Glass-sponge}, in the Vocabulary.

   {Glove sponge}, a variety of commercial sponge ({Spongia
      officinalis}, variety {tubulufera}), having very fine
      fibers, native of Florida, and the West Indies.

   {Grass sponge}, any one of several varieties of coarse
      commercial sponges having the surface irregularly tufted,
      as {Spongia graminea}, and {S. equina}, variety
      {cerebriformis}, of Florida and the West Indies.

   {Horse sponge}, a coarse commercial sponge, especially
      {Spongia equina}.

   {Platinum sponge}. (Chem.) See under {Platinum}.

   {Pyrotechnical sponge}, a substance made of mushrooms or
      fungi, which are boiled in water, dried, and beaten, then
      put in a strong lye prepared with saltpeter, and again
      dried in an oven. This makes the black match, or tinder,
      brought from Germany.

   {Sheep's-wool sponge}, a fine and durable commercial sponge
      ({Spongia equina}, variety {gossypina}) found in Florida
      and the West Indies. The surface is covered with larger
      and smaller tufts, having the oscula between them.

   {Sponge cake}, a kind of sweet cake which is light and
      spongy.

   {Sponge lead}, or {Spongy lead} (Chem.), metallic lead
      brought to a spongy form by reduction of lead salts, or by
      compressing finely divided lead; -- used in secondary
      batteries and otherwise.

   {Sponge tree} (Bot.), a tropical leguminous tree ({Acacia
      Farnesiana}), with deliciously fragrant flowers, which are
      used in perfumery.

   {Toilet sponge}, a very fine and superior variety of
      Mediterranean sponge ({Spongia officinalis}, variety
      {Mediterranea}); -- called also {turkish sponge}.

   {To set a sponge} (Cookery), to leaven a small mass of flour,
      to be used in leavening a larger quantity.

   {To throw up the sponge}, to give up a contest; to
      acknowledge defeat; -- from a custom of the prize ring,
      the person employed to sponge a pugilist between rounds
      throwing his sponge in the air in token of defeat. [Cant
      or Slang] ``He was too brave a man to throw up the sponge
      to fate.'' --Lowell.

Platinum \Plat"i*num\, n. [NL., fr. Sp. platina, from plata
   silver, LL. plata a thin plate of metal. See {Plate}, and cf.
   {Platina}.] (Chem.)
   A metallic element, intermediate in value between silver and
   gold, occurring native or alloyed with other metals, also as
   the platinum arsenide (sperrylite). It is heavy tin-white
   metal which is ductile and malleable, but very infusible, and
   characterized by its resistance to strong chemical reagents.
   It is used for crucibles, for stills for sulphuric acid,
   rarely for coin, and in the form of foil and wire for many
   purposes. Specific gravity 21.5. Atomic weight 194.3. Symbol
   Pt. Formerly called {platina}.

   {Platinum black} (Chem.), a soft, dull black powder,
      consisting of finely divided metallic platinum obtained by
      reduction and precipitation from its solutions. It absorbs
      oxygen to a high degree, and is employed as an oxidizer.
      

   {Platinum lamp} (Elec.), a kind of incandescent lamp of which
      the luminous medium is platinum. See under {Incandescent}.
      

   {Platinum metals} (Chem.), the group of metallic elements
      which in their chemical and physical properties resemble
      platinum. These consist of the light platinum group, viz.,
      rhodium, ruthenium, and palladium, whose specific
      gravities are about 12; and the heavy platinum group,
      viz., osmium, iridium, and platinum, whose specific
      gravities are over 21.

   {Platinum sponge} (Chem.), metallic platinum in a gray,
      porous, spongy form, obtained by reducing the double
      chloride of platinum and ammonium. It absorbs oxygen,
      hydrogen, and certain other gases, to a high degree, and
      is employed as an agent in oxidizing.