346 OENERAL ANATOMY. 



cous substance analogous to the cellular tissue, and which, in 

 their ordinary state, must be an extreme degree of compact- 

 ness and condensation. 



544. Cartilages contain a great quantity of water* or se- 

 rous liquid, which oozes at the surface when it is cut, and 

 which moistens it. In the adult man the proportion of water 

 that they contain is to the solid substance as 2i is to 1. Dried 

 cartilages become semi-transparent, yellowish, and susceptible 

 of being torn; steeped in water it resumes in four days its 

 weight and volume, its white colour, its flexibility, and partly 

 loses its transparency. 



545. Submitted to the action of boiling water when in thin 

 lamina?, it at first crisps them and renders them yellow and 

 opaque. 



The prolonged action of the boiling water on cartilages es- 

 tablishes between them a difference founded also on other 

 character; the cartilages of the joints are reduced into a jelly 

 by decoction, the other, on the contrary, resist its action. Al- 

 cohol renders cartilages slightly opaque. Diluted acids have 

 no action upon them ; when concentrated, they act as upon 

 the epidermis. Their chemical analysis is as yet imperfect. 

 It has been vaguely repeated, after Haller, that they are com- 

 posed of gelatine and earth. According to M. Allen, they are 

 composed of gelatine, and a hundredth of carbonate of lime. 

 Hatchett says that they are formed of coagulated albumen and 

 traces of phosphate of lime ; but we do not know to which 

 cartilages he alludes. M. Chevreul has found that the cartila- 

 ginous bones of the shark (sgualus) are composed of oil, mu- 

 cus, acitic acid, and some salts. J. Davy has found cartilages 

 formed of albumen 44, 5; water 55; and phosphate of lime 0, 5. 



546. The physical property the most remarkable of the 

 cartilages is elasticity. They do not elongate and return on 

 themselves, like the elastic tissue; they generally do not yield 

 to pressure, like the chondroid ligaments, and afterwards re- 

 sume their thickness; but they are flexible, and return to their 



* Chevreul, de f influence gue Feau exerce, &c. Jlnnaks de Chimie et de 

 Physique, tome 19. 



