The Collaborative International Dictionary of English v.0.48:

Speiss \Speiss\, n. [Cf. G. speise food, mixed metal for bells,
   etc.]
   1. (Metal.) A regulus consisting essentially of nickel,
      obtained as a residue in fusing cobalt and nickel ores
      with silica and sodium carbonate to make smalt.
      [1913 Webster]

   2. (Metal.) Impure metallic arsenides, principally of iron,
      produced in copper and lead smelting.
      [Webster 1913 Suppl.]