Kelp
From BiblePortal Wikipedia
Webster's Dictionary [1]
(1): ( n.) The calcined ashes of seaweed, - formerly much used in the manufacture of glass, now used in the manufacture of iodine.
(2): ( n.) Any large blackish seaweed.
The Nuttall Encyclopedia [2]
An alkaline substance derived from the ashes of certain sea-weeds, yielding iodine, soda, potass, and certain oils; kelp-burning was formerly a valuable industry in Orkney and the Hebrides.
