FISHES AND MANKIND 401 



from the inner lining of the air-bladder of certain fishes, and is 

 principally used for the clarification of wines and beer, for 

 making jellies, etc., and in the preparation of certain cements. 

 It is made in various parts of the world from the air-bladders, 

 or "sounds," as they are known to the trade, of such diverse 

 fishes as the Sturgeons, Carps, Cat-fishes, Cod, Ling, Hake, 

 Squeteagues, Drums, and Thread Fins. The Russian isinglass, 

 marketed as "leaf," "pipe," and "cake," is perhaps best known 

 and of the finest quality, being manufactured entirely from the 

 sounds of various species of Sturgeon. 



The skins of some fishes, and particularly those of the Sharks 

 and Rays, are sometimes of use to mankind. With the bony 

 dermal denticles in situ, the crude skins of Sharks and Dog-fishes 

 are used by carpenters and cabinet-makers for smoothing and 

 pohshing, as well as by metal-workers; suitably prepared and 

 dyed skins provide the shagreen used for covering car cases, 

 jewel boxes, sword scabbards, and for ornamental work of all 

 kinds. After being specially tanned, and having had the dermal 

 denticles removed, the skins of most Sharks and Rays provide 

 a strong and highly durable leather, and with the increasing 

 demand for this commodity in recent years the shark-leather 

 industry is fast becoming a satisfactory commercial proposition. 

 Recently, experiments have been made with the skins of some 

 of the Bony Fishes, the Wolf-fish (known to the trade as "Sea 

 Leopard"), Cod, Bream, Corvina, and Sole being most popular, 

 but, although these are in some demand for fancy work, they 

 lack the durabiUty of shark leather. In certain of the Islands 

 of the South Seas the natives make use of the dried and spiny 

 skins of the Globe-fishes or Porcupine-fishes for war helmets, 

 and in Japan it is a common practice to make lanterns out of 

 the inflated and dried skins of Puffers, by cutting out the back 

 and suspending the fish by a wire. A candle being placed 

 inside, the light shines as brightly through the stretched skin 

 of the fish as through a piece of oiled paper. 



Finally, the silvery scales of the Bleak (Alburnus), a Cyprinid 

 fish found all over Europe north of the Pyrenees and Alps, are 

 used extensively in the manufacture of artificial pearls, especially 

 in France, where the industry dates from the middle of the 

 seventeenth century. A pigment is obtained by scraping the 

 scales, which is coated on the inside of hollow glass beads, and 

 these are then filled with wax. 



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