IODINE AND OTHER CHEMICALS 75 



cystis pyrifera, is leached with water, until most of 

 the salts are washed out, and then highly compressed 

 and dried. The dried product resembles in appear- 

 ance ebonite or vulcanized fiber. Certain species of 

 laminaria, which have a hollow stipe and when dry 

 are hard and horny, are made into knife-handles. 



A submarine plant knowTi as Posidonia australia, 

 found on the southern coast of South Australia, 

 contains a valuable fiber which is used in the manu- 

 facture of cloth, rope, twine, mats, paper, and stuff- 

 ing. The fiber which is used commercially is obtained 

 from large deposits of the dead plant in Moonta 

 Bay, South Australia, where it is found to a depth 

 of nine feet. 



Certain laminaria contain a considerable amount 

 of the sugar, mannite ; methods have been proposed 

 for preparing manna from these algae. The natives 

 of Kamchatka prepare an alcoholic drink by the 

 fermentation of the dulse. 



In the British Isles, France, and Holland, large 

 quantities of eel-grass are dried and used in the 

 stufiing of mattresses and upholstery. This marine 

 plant thrives only on muddy bottoms in shallow 

 water in protected places. Since the grass does not 

 grow above the low-water mark, it is necessary for 

 the men who harvest the plant to mow the grass in 

 shallow water at low tide. It is cured by alternate 

 drying and soaking. Immediately upon harvesting, 

 the grass is dried upon the beach. When nearly dried 

 it is soaked in ditches filled with fresh water. Then 

 it is dried again; this process is repeated until it is 

 very black. After the final drying it is taken to 



