ASHES OF CARTILAGE. 229 



By long boiling in water the elastic tissue affords a sub- 

 stance somewhat resembling gelatine ; more than a half, how- 

 ever, remains un dissolved. 



Cartilage. Gristle is known to anatomists by the name of 

 cartilage. This texture is distinguished by its great elasticity. 

 It readily yields to pressure or torsion, but immediately re- 

 covers its original shape when the force applied is withdrawn. 

 Along with bone and the substances of the teeth, it constitutes 

 the hard solids. It is somewhat less than twice the density of 

 water. 



In the early embryo, the skeleton is in great part cartilagin- 

 ous, which texture in due time gives place to bone. The chief 

 of the permanent cartilages are the articular and the costal 

 cartilages. Others again enter into the external ear, the nose, 

 the eyelids, the Eustachian tube, the larynx, and the windpipe. 

 Cartilages, except those of the joints, are. covered by fibrous 

 membrane termed perichondrium. 



When a thin slice of cartilage is examined with the micro- 

 scope, it is found to consist of nucleated cells disseminated in 

 a solid mass or matrix. 



Ordinary permanent cartilage is resolved by long boiling 

 into chondrine. 



Of the ashes of cartilage 100 parts consist of 



Carbonate of soda, .... 35.07 

 Sulphate of soda, . . . .24.24 



Chloride of sodium, .... 8.23 



Phosphate of soda, . . . . 0.92 



Sulphate of potash, .... 1.20 



Carbonate of lime, .... 18.37 



Phosphate of liine, .... 4.06 



Phosphate of magnesia, . . . 6.91 



Oxide of iron and loss, . . . . 1.00 



100.00 

 Fibro-Cartilage. Fibro- cartilage is a compound of car- 



