ALG A. 769 
 properties.—L. bulbosa, L. digitata, and L. saccharina are used to a very 
large extent for manure and for the preparation of kelp. The latter is also 
frequently used as an hygrometer. JL. digitata also contains much iodine. 
Laurencia.—L,. pinnatifida is remarkable for possessing pungent proper- 
ties. It is called Pepper-dulse in Scotland, where it is occasionally eaten. 
Berkeley says that ZL. obtusa forms tbe greater part of what is now sold in 
the shops as Corsican Moss. (See Gracilaria).— L. papillosa (Tanshwui) 
is extensively employed in China and Japan in the preparation of a gela- 
tinous substance called Yang-Tasi. 
Nostoc.— WN. edule is eaten in China, &c. Other species are also edible. 
(See Hormosiphon arcticus.) 
Porphyra laciniata and P. vulgaris are employed in the preparation of a 
kind of sauce or pickle, which is termed Sloke, Slokan, or Laver.—P. vul- 
garis is eaten in China as a relish to rice. It is termed Tsz-T'sai (purple 
vegetable). It is also used for food by many of the Indians along the 
Pacific coast, being cooked separately as greens, or with meat. 
Rhodymenia palmata is an article of food in Scotland, Ireland, Iceland, 
&ec. It is the Dulse of the Scotch, and the Dillesk of the Irish. 
Sargassum.—S. bacciferum is the Gulf-weed of the Atlantic. This and 
other species contain iodine, to the presence of which they owe their bene- 
ficial effects in goitre, fur which purpose stem-like pieces of S. bacciferum 
are much employed in South America under the name of Goitre-sticks. 
Ulva latissima is employed in the preparation of Green Laver. It is 
very inferior to the laver prepared from species of Porphyra. Both these 
lavers might be beneticial in scrofulous affections, &c., as they contain 
iodine, 
