Kelp
The mineral residue or ash obtained by burning different kinds of seaweed. It was formerly of great commercial value and importance, as the source of the carbonate of soda used in glass and soap making, &c. From the quantity of potash which Kelp contains (17.5 per cent.), and the importance of this as an ingredient of soils, its value is at once apparent. It has been applied, with more or less success, to crops of Potatoes, Broccoli, Cabbage, &c.