Seaweed and its Uses. 325 



distance by the steamers which quit Saigon for Tonkin and 

 China. 



There is another species of algae which has not the 

 same utility, but which has a certain relative importance, 

 as it is used medicinally, being administered to patients 

 in different forms of drugs, cataplasms, moxas, etc. This 

 species is called hai-toc, or " beard of the rocks." It has a 

 fine green colour. The filaments are very slender, and are 

 agitated in the manner of a fish's tail by the least move- 

 ment of the water. The large and immense roadstead of 

 Touranne contains great quantities. This hai-toc is found 

 at shallow depths, attached by preference to old pieces of 

 wood, piles, etc. 



The Annamites designate the gelatine obtained from 

 seaweeds by the name of tao. The Malays call it, as 

 already stated, agar-agar. It is not prepared with the 

 same care as in China and Japan, and is only shipped to 

 China, in consequence of its low price. 



The Annamites give the name of rau-cau to several 

 species of algae (Conferva corallina, Gelidiwn spiniforme, etc.) 

 which they collect from the rocks on the islands of Cu-lao- 

 Khai (province of Binh Thuan) and Cu-lao-re (province of 

 Quang-ngai). They are known in Chinese medicine under 

 the name of hai-thao. 



Fifteen hundred grammes of rau-cau yield about two 

 litres of seaweed jelly, which is much used for food pur- 

 poses, after adding sugar, spirit, or other flavouring to suit 

 the palate. This jelly also serves to make the gelose, or sea- 

 weed isinglass, which has been popularly employed of late 

 years in France for culinary purposes, by confectioners, for 

 sizing fabrics, and for preparing gold-beater's skin. The 

 best seaweed is obtained from the island of Cu-lao-re. 

 The first-quality gelose, known as rau-cau-ckon-vit, is white 



