THALLOGENiE. 721 



Durvilltsa utilis is used.for food by the poorer inhabitants on the western 

 coast of South America. 



Halidrys siliquosa contains nearly 6 per cent, of mannite. 



Sargassum, — S. bacciferum is the Gulf- Weed of the Atlantic. This and 

 other species contain iodine, to the presence of which they owe their beneficial 

 eflTects in Goitre, for which purpose stems of the S. bacciferum are much em- 

 ployed in South America under the name of Goitre-sticks. 



Iridcea edulis, as its name implies, is nutritious, and is sometimes used for 

 food in Scotland, &c. 



Chondrus {Sphisrococcus). — C. crispus is commonly termed Carrageen or 

 Irish Moss. It possesses nutritive, emollient, and demulcent properties, and 

 may be used in the form of a decoction, jelly, &c., in pulmonary complaints, 

 &c. Bandoline or fixature, used for stiffening the hair, &c., is generally pre- 

 pared from Carrageen. C. mamillosus is always found in the Carrageen 

 Moss of the shops. Its properties are similar. Carrageen Moss is sometimes 

 employed as a substitute for size. 



Gelidium corneuni, as already noticed, is nutritive. It is the Algue de Java, 

 from which M. Payen first obtained Gelose. It forms a favourite article of 

 food in Japan, &c., and is also used in the manufacture of a kind of glue, &c. 



Gigartina speciosa is another edible Alga, in common use for food in certain 

 parts of Australia, &c. 



Laurencia. — L. pinnat?fida is remarkable for possessing pungent proper- 

 ties. It is called Pepper-dulse in Scotland, where it is occasionally eaten. 

 L. papulosa (Tan-shwui), is extensively employed in China and Japan in the 

 preparation of a gelatinous substance called Yang-Tsai. 



Gracilaria {Plocaria).—G. lichenoides or Plocaria Candida, is our commer- 

 cial Ceylon Moss. It is nutritive, emollient, and demulcent, and may be em- 

 ployed in the form of a decoction or jelly, as a food for children and invalids, 

 and medicinally, in pulmonary complaints, diarrhoea, &c. It is sometimes 

 imported under the name of Agar-agar, but G. spinosa (Fucus spinosus or 

 Eucheuma spinosa), has been also imported under the same name. Both 

 species are largely employed in the East for making nutritious jellies, for 

 stiflTening purposes, and for varnishing. G. tentix may be similarly used. 

 Gracilaria or Plocaria Helminthocorton is Corsican Moss. It has been used 

 principally as a vermifuge, but its properties have been much overrated. G. 

 crassa (Ki-tsai), is cooked with soy or vinegar in China. It is also employed 

 by the Chinese ladies to give a glossiness to their hair. 



Rhodomenia palmata is an article of food in Scotland, Ireland, Iceland, &c. 

 It is the Dulse of the Scotch, and the DiUesk of the Irish. 



Porphyra laciniata and vulgaris are employed in the preparation of a kind 

 of sauce or pickle, which is termed Sloke, Slokan, or Laver. P. vulgaris is 

 eaten in China as a relish to rice. It is termed Tsz-Tsai (purple vegetable). 



Viva latissima is employed in the preparation of Green Laver. It is very 

 inferior to the laver prepared from the species of Porphyra. Both these lavers 

 might be beneficial in scrofulous affections, &c., as they contain iodine. 



Nostoc.—N. edule is eaten in China, &c. N, arcticum is a valuable article 

 of food in the Arctic regions ; it is said by some to be far superior in this 

 respect to Iceland Moss. Other species possess similar properties. 



Artificial Analysis of the Natural Orders in the Sub-class 

 Thallogen^. 



(The numbers refer to the Orders.) 



1. Plants with a mycelium, growing in or on decaying or liv- 



ing organic matter, and fructifying in the air . . . Fungi. 294. 



2. Plants without a mycelium. 



Living and fructifying in the air Lichenes. 293. 



Living in water, or in very moist situations . . . .Alga. 295. 



3 A 2 



