256 FISHES OF AUSTRALIA. 



ray (Dasyatis scphen} which is found on the coasts of New 

 South Wales and Queensland, and also in the Indian Ocean, 

 the Red Sea and the Mediterranean Sea. This skin is re- 

 markable for the size of the numerous round, hard protuber- 

 ances on the skin. These become white by rubbing down, 

 the interior being opaque and nacreous. The skin is some- 

 times dyed in various colours, but is often left the natural 

 colour, by only half polishing it. Even at the present day 

 the skin from some of the smaller Sharks is used by certain 

 turners, and workers in ebony and ivory, as it is more even 

 and more durable than glass-, sand- or emery-paper. Many 

 miscellaneous skins are valued principally because of their 

 peculiar grains or markings, and are so tanned, as to bring 

 their grains into prominence. These are used principally 

 in small articles such as belts, card-cases, pocket-books, etc., 

 or for covering boxes, writing-cases, sword-grips, etc. 



Fish-skins are employed extensively in the preparation 

 of fish-glue. 



The Scales of Fishes are used to some extent in the 

 manufacture of glue, and also (recently) in the preparation 

 of gelatine. They are also used for purposes of ornamen- 

 tation and for the manufacture of artificial flowers. In 

 1875 the Royal University of Norway, Christiania, sent to 

 the Smithsonian Institute, Washington, U.S.A., a diadem, 

 made from fish-scales and eyes. Ornaments for ladies, 

 made from fish-scales, were, at one time, largely sold at the 

 Crystal Palace, London. The Chinese are said to have a 

 mode of grinding up fish-scales and using the powder as a 

 dry pigment, to give a brilliancy to parts of pictures. In 

 some parts of the world, the scales of large fishes such as 

 the Tarpon of America- are treated in such a way, as to 

 make them appear like mother-o'-pearl. They are then 

 worked up into artificial flowers, marquetry articles and 

 other fancy works and in some cases, little scenes are painted 

 on them. 



Guanin : The perfectly white solution of the scales of 

 the Bleak (Alburnus lucidus), is now used largely in the 

 production of artificial pearls. This substance is an excre- 

 mentitious matter, known as "Guanin." Glass bulbs, in the 

 shape of pearls, lined with this substance, make a very close 



