40 CARTILAGE. 



CARTILAGE. 



CARTILAGE belongs to that class of tissues which, although they 

 appear to act for the most part mechanically, and to possess a 

 small amount of vital activity, nevertheless exhibit a tolerably 

 composite and very varied structure. 



Histological investigations show that cartilage must be classed 

 under at least two heads, depending upon structural differences : 

 namely, true cartilage and fibro-cartilage. 



Amongst the true cartilages of the human body we must include 

 those of the ribs, the ensiform cartilage, the cartilages of the nose, 

 of the larynx and trachea, and the cartilaginous masses investing 

 the articular heads of bone. This true cartilage is so far identical 

 in character in these parts of the organism, that it exhibits in all 

 cases more or less numerous cavities occurring in a tolerably homo- 

 geneous mass, and containing one or more cells with a simple 

 nucleus. This matrix is by no means perfectly amorphous ; in 

 most cases it is finely granulated, but frequently it is fibrous. 



The fibro -cartilage composing the intervertebral ligaments, the 

 symphysis pubis, the claviculo-scapular ligaments, the Eustachian 

 tube, &c., contains, in addition to cells, a thoroughly fibrous 

 matrix ; these fibres are either parallel to, or intersect one another 

 in various directions, present sharp dark outlines, and exhibit no 

 trace of nuclei. 



These differences, which the microscope reveals in cartilage, 

 admit equally of recognition by means of chemical investigation. 

 Miiller's* observations, which were the earliest prosecuted in rela- 

 tion to this subject, have been followed in more recent times by 

 those of Donders and Mulder.f 



When we examine this tolerably homogeneous matrix of true 

 cartilage in a chemical point of view, we find, on carefully treating 

 the triturated cartilage with boiling water, that it is this substance, 

 and not the cartilage-cells, which yields the chondrin described in 

 vol. i, p. 398. Thus, for instance, if we boil the cartilage of the 

 ribs from 12 to 48 hours in the open air (Mulder), or from three 

 quarters of an hour to an hour in a Papin's digester (HoppeJ), the 

 matrix will be dissolved, leaving only the other morphological 



* Fogg. Ann. Bd. 38, S. 295. 



t Versuch einer phys. Chem. S. G58 [or English Translation, pp. 545-559.] 



J De cartilaginum structura et chondrino, diss. inaug. Berol. 1850. 



