XXXI 



IVORY 



From time immemorial certain natural prorluctions 

 ill the mineral and animal world have Ijeen highly 

 esteemed for artistic and decorative purposes. Amoiio- 

 such substances gold, silver, marble, precious stones, 

 and ivory have held leading places. 



Among these materials ivory holds a peculiar 

 position, inasmuch as it is the most durable substance 

 furnished by the animal kingdom. Moreover, ivorj', like 

 gold, silver, and diamonds, cannot be made artificially, 

 and no satisfactory substitute has been devised to 

 supply its place in the various arts and industries of the 

 civilised world. 



Ivory is known to anatomists as dentine and it 

 enters into the formation of the teeth of mammals, l)ut 

 the term ivory is restricted by use to the dentine of 

 those animals in which it occurs in suthcient quantity 

 to be useful for industrial and artistic purposes. Such 

 mammals are the elephant, hippoj)otamus, narwhal, 

 sperm-whale, and walrus. 



Tlie chief source of the best ivor}^ to-day is the 

 tusks of the iVfrican elephant. The tusks a.re the 

 permanent upper incisors of this huge mammal ; they 

 not only surpass other teeth as belonging to an animal 

 so enormous, but they are the largest of all teeth in 



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