MAEINE ALG^ OF THE UNITED STATES. 717 



USED FOR THE MANUFACTURE OF IODINE. 



The rock-weeds' and kelp furnish nearly all the iodine of commerce. 

 The largest manufactories of iodine are in Scotland, where use is made 

 of the same species of JFucus and Laminaria as are common on the 

 New England coast. 



THE GREAT KELP OF CALIFORNIA. 



Macrocystis pyrifera forms entangled masses, which serve as 

 natural breakwaters on the exposed portion of the California coast. 

 The leaf-bladders of the same plant are used by sailors in high southern 

 latitudes for rolling up into cigarettes. 



The very long slender stems of Nereocystis Lutkeana, the Great 

 bladder -weed, of the west coast, are used as fish-lines by the Indians of 

 the Northwest. 



The rough-dried stems of Laminaria saccarhina, L. longicruris, 

 L. flexicaulis, and other large species of Laminaria, under the name 

 of Artificial staghorn, are used for making handles to knives, paper-cut- 

 ters, and other ornamental purposes. At one time, an attempt was made 

 to establish a manufactory of buttons out of dried Laminaria stems at 

 Marblehead ; but the attempt was given up, as the buttons did not bear 

 washing. 



The dry stems of the Laminariae, particularly the digitate species, as 

 L. flexicaulis, are used by surgical-instrument makers in the manu- 

 facture of sponge-tents. 



Corallina officinalis, L., was formerly used in medicine as a tonic. 



