CARTILAGE. 521 



of the ox, namely, 0.5814 gram per kilo of dried substance. In man he 

 found 0.0637 gram in the tendons, 0.1064 gram in the fascia, and 0.244 

 gram in Wharton's jelly for every kilo of dried substance. The quantity 

 of silicic acid is higher in the young than in the old; in man it is highest 

 in the embryonic connective tissue of the umbilical cord. In the last- 

 named substance SCHULZ also found 0.403 gram Fe 2 3 , 0.693 gram 

 MgO, 3.297 grams CaO, and 3.794 grams P 2 O 5 for every kilo of dried 

 substance. The report of SCHULZ on the quantity of silicic acid does 

 not correspond with the recent investigations of FRAUENBERGER l who 

 found, in Wharton's jelly, about one-twentieth the quantity of silicic acid 

 that SCHULZ gives. 



II. CARTILAGE. 



Cartilaginous tissues consist of cells and an original hyaline matrix, 

 which, however, may become changed in such wise that there appears 

 in it a network of elastic fibres or connective-tissue fibrils. 



Those cells that offer great resistance to the action of alkalies and 

 acids have not been carefully studied. According to earlier opinions the 

 matrix was considered as consisting of a body analogous to collagen, 

 so-called chondrigen. The recent investigations of MOROCHOWETZ and 

 others, but especially those of C. M6RNER, 2 have shown that the matrix 

 of the cartilage consists of a mixture of collagen with other bodies. 



The tracheal, thyroideal, cricoidal, and arytenoidal cartilages of 

 full-grown cattle contain, according to MORNER, four constituents in 

 the matrix, namely, chondromucoid, chondroitin-sulphuric acid, collagen, 

 and the albumoid. 



Chondromucoid. This body, according to C. MORNER, has the com- 

 position C 47.30, H 6.42, N 12.58, S 2.42, O 31.28 per cent. Sulphur is 

 in part loosely combined and may be split off by the action of alkalies, 

 and a part separates as sulphuric acid when boiled with hydrochloric 

 acid. Chondromucoid is decomposed by dilute alkalies and yields alkali 

 albuminate, peptone substances, chondroitin-sulphuric acid, alkali sul- 

 phides, and some alkali sulphates. On boiling with acids it yields acid 

 albuminate, peptone substances, chondroitin-sulphuric acid, and on 

 account of the further decomposition of this last body, sulphuric acid 

 and a reducing substance are formed. 



Chondromucoid is a white, amorphous, acid-reacting powder which 

 is insoluble in water, but dissolves easily on the addition of a little alkali. 

 This solution is precipitated by acetic acid in great excess and by small 



1 Schulz, Pfliiger's Arch., 84 and 89; Frauenberger, Zeitschr. f. physiol. Chem., 57. 



2 Morochowetz, Verhandl. d. naturh. med. Vereins zu Heidelberg, 1, Heft 5; Morner, 

 Skand. Arch. f. Physiol., 1. 



