252 SKELETON. 



and of parts which they have in common with other organs. 

 The first has some very distinguishing properties. It resists 

 putrefaction, either with or without maceration, longer than any 

 other tissue, except the bones. In the midst of gangrene it pre- 

 serves its appearance almost unchanged. Boiling gives it a yel- 

 low colour, causes it to swell, and, if protracted, the gelatinous 

 portion is dissolved. When dried, it becomes of a semi-trans- 

 parent yellow, diminishes Fn bulk, and loses its elasticity ; in 

 these respects resembling ligaments and tendons. 



Cellular substance exists, in very small quantities, in carti- 

 lage, and is therefore, not readily demonstrated; it is, however, 

 made manifest by maceration, and by the action of boiling wa- 

 ter: the latter, by dissolving the gelatinous portion, leaves a 

 membranous and cellular structure. It is also stated, that in 

 certain diseases, the gelatinous portion being less abundantly 

 secreted, the cellular is left in a soft spongy condition. 



In a healthy state, no blood vessels can be seen in cartilages; 

 yet there are the strongest proofs of a species of circulation go- 

 ing on in them, either by very fine capillary vessels, or an in- 

 terstitial absorption. All experienced anatomists have seen, in 

 subjects affected with jaundice, the entire cartilaginous system 

 losing its brilliant whiteness, and becoming of a light yellow: 

 also, the conversion into bone, in extreme old age, to which all 

 cartilages, with but few, perhaps no exceptions, are subject ; and 

 this ossification sometimes beginning in the centre of the carti- 

 lage, prove that the calcareous matter has been conveyed there 

 by some kind of channel. 



Neither absorbents nor nerves have been traced into them, 

 and it is not possible to prove conclusively, their existence by 

 the circumstances of disease. We only know, that in inflam- 

 mations of the joints, terminating by anchylosis, the cartilages 

 are absorbed ; and that in some cases, even without evident in- 

 flammation, the cartilage is removed from a joint as if it had 

 been worn away. Ulcerations of the arytenoid cartilages are 

 spoken of as common, by the French anatomists;* but it has 

 not occurred to me to see either them or any others in this 

 state : the late Dr. Physick's experience is also the same with 



* I have, since the first edition of this work, seen several instances in _chronic 

 Laryngitis. 



