122 BiUTisH SEA- WEEDS, \_21elanospermea . 



dressed them, upon pieces of the fossil alkali. The river- 

 sand above which this operation was performed was vitrified 

 bj its union with the alkali, and thus produced glass. The 

 important hint thus accidentally obtained was soon adopted, 

 and tlie art of making glass was gradually improved." 

 Though kelp till lately was chiefly employed in Britain in 

 the manufacture of glass and soap, it is now, as we have 

 already stated, principally manufactured for the iodine it 

 cgntains, and no Sea-weed is so rich in iodine as this great 

 tangle, especially its woody stems. At a kelp-kiln which 

 we saw in operation at the Giant's Causeway last September, 

 we observed that the kelp-burners were using only the 

 woody stems of Laminaiia digitata, great bundles of which 

 were spread around ready to be cast into the furnace. The 

 kelp seemed very rich, and we doubt not would yield much 

 iodine. 



2. Laminaeia bulbosa, Lamour. Bidhoiis-rooted Tangle; 

 Sea-furleloivs ; Furheloiced-hancjers, 



Hab. In the sea, in deep water. Perennial. 



"When in a young state, the frond is plane and undivided, 

 the stem short, with a knob near the root, which is com- 

 posed of fibres. As the growth of the jilant proceeds, the 

 stem becomes flat, and when fully grown it is waved and 



