The kelp industry, formerly of at least minor importance, has ceased.
It was hard, smooth sand, very different from the loose, sharp sand, mingled with kelp and shells, at Brewster.
The linen trade introduced in the middle of the 18th century is extinct, and a like fate has overtaken the kelp and straw-plaiting industries.
Iodine is obtained either from kelp (the ashes of burnt seaweed) or from the mother-liquors obtained in the purification of Chile saltpetre.
The product obtained after burning is known either as kelp or varec. Another method of obtaining kelp is to heat the seaweed in large retorts, whereby tarry and ammoniacal liquors pass over and a very porous residue of kelp remains.