550 TISSUES OF THE CONNECTIVE SUBSTANCE. 



extent in all matrices, and of these it is richest in the cartilage. Ten- 

 dons, ligamentum nuchse, and cartilage of the ox contained 0.06, 0.07, 

 and 2.17 p. m. glycogen respectively (HANDEL). 



HOPPE-SEYLER found in fresh human rib-cartilage 676.7 p. m. water, 

 301.3 p. m. organic, and 22 p. m. inorganic substance, and in the cartilage 

 of the knee-joint 735.9 p. m. water, 248.7 p. m. organic, and 15.4 p. m. 

 inorganic substance. PICKARDT found 402-574 p. m. water and 72.86 

 p. m. ash (no iron) in the laryngeal cartilage of oxen. The ash of car- 

 tilage contains considerable amounts (even 800 p. m.) of alkali sulphate, 

 which probably does not exist originally as such, but is produced in great 

 part by the incineration of the chondroitin-sulphuric acid and the chon-' 

 dromucoid. The analyses of the ash of cartilage therefore cannot 

 give a correct idea of the quantity of mineral bodies existing in this sub- 

 stance. The cartilage is richest in sodium of all the tissues of the body, 

 and according to BUNGE l the amount of Na and Cl is greatest in young 

 animals. In 1000 parts of cartilage dried at 120 C., BUNGE found 91.26 

 parts Na2O in the shark, 33.98 in the ox embryo, 32.45 in a fourteen-day- 

 old calf, and 26.4 in a ten-weeks-old calf. 



Ochronose is the brown to black coloration of the cartilage which 

 sometimes occurs, and which has also been observed in several cases of 

 alcaptonuria (see Chapter XIV) or after lengthy treatment with carbolic 

 acid bandages (POULSEN, ADLER 2 ) . The nature of these melanine- 

 like pigments is unknown. 



The Cornea. The corneal tissue, which, in a chemical sense, is con- 

 sidered by many investigators to be related to cartilage, contains traces 

 of proteid and a collagen as chief constituent, which C. MORNER 3 claims 

 contains 16.95 per cent N. According to him it also contains a mucoid 

 which has the composition C 50.16, H 6.97, N 12.79, and S 2.07 per 

 cent. On boiling with dilute mineral acid this mucoid yields a reducing 

 substance. The globulins found by other investigators in the cornea 

 are not derived from the matrix, according to MORNER, but from the 

 layer of epithelium. MORNER believes that DESCEMET'S membrane 

 consists of membranin (page 171), which contains 14.77 per cent N and 

 0.90 per cent S. 



In the cornea of oxen His 4 found 758.3 p. m. water, 203.8 p. m. 

 gelatin-forming substance, 28.4 p. m. other organic substance, besides 

 8.1 p. m. soluble and 1.1 p. m. insoluble salts. 



1 Hoppe-Seyler, cited from Kiihne's Lehrbuch d. physiol. Chem., 387; Pickardt, 

 Centralbl. f. Physiol., 6, 735; Bunge, Zeitschr. f. physiol. Chem., 28. 



2 See Maly's Jahresb., 40, 424, Adler, Zeitschr. f. Krebsforschung, 11. 



3 Zeitschr. f. physiol. Chem., 18. 



4 Cited from Gamgee, Physiol. Chem., 1880, 451. 



