CHAP. VII.] THE CONNECTIVE TISSUES. 209 



Costal Articular Cartilages 



Cartilages. from knee joint. 



Water in 100 parts 67'67 73'59 



Organic matters 3013 24'87 



Mineral 2*20 1'54 



Tlie following are the results of Hoppe's analysis of the ashes of 

 human costal cartilage. 



Potassium sulphate in 100 parts 26*66 



Sodium 44-81 



chloride 6*11 



phosphate 8'42 



Calcium 7*83 



Magnesium 4*55 



Chondrigen. 





The substance of which the matrix of hyaline cartilage and the 

 capsules of the cartilage cells in the other forms of cartilage is 

 composed, resembles in many particulars collagen, but differs from it 

 in the product which it yields by the prolonged action of boiling 

 water. As it is generally believed that by this action a body to 

 which the term Chondrin has been given is formed, the mother 

 substance has received the name of Chondrigen. 



Chondrigen is unacted upon by cold water, and swells very 

 slightly in acetic acid. It is dissolved by concentrated mineral acids 

 and caustic alkalies. When heated (in sealed glass tubes or in a 

 Papin's digester) in water at a temperature of 120C. for three or 

 four hours chondrigen dissolves ; the solution contains chondrin. 



Chondrin. 



Costal cartilage is boiled for a few minutes, arid 

 Preparation. ,, ,, i i 



is then scraped so as to remove the penchondrium. 



It is then finely divided and boiled for twenty-four hours with water ; 

 or placed in a Papin's digester, and heated in water at 120C., for 

 three or four hours. The solution thus obtained is filtered so as to 

 separate it from insoluble matters, such as elastic tissue, cellular 

 elements, &c., and it is then precipitated with acetic acid. The pre- 

 cipitate is then extracted with alcohol or ether. It may be again 

 dissolved in hot water and the solution poured into a large excess 

 of absolute alcohol, when the chondrin which precipitates is separated 

 and dried. When dry it presents the appearance of a hard, trans- 

 parent mass, devoid of smell and taste l . 



General re- Chondrin is insoluble in cold water, in alcohol, 



actions. ether, or chloroform. It is soluble in hot water, and 



aqueous solutions of chondrin gelatinize exactly like 



1 The description of the preparation of Chondrin is mainly borrowed from Gautier, 

 Chimie Appliquee, <&c., Vol. i., p. 346. 



