1 14 THE CHEMISTR Y OF THE TISSUES AND ORGANS. 
great bulk of the organic solids is derived from the matrix of the 
cartilage. 
In fibrocartilage, the hyaline matrix is"pervaded either by white 
fibres (white fibrocartilage), 01 by yellow fibres (yellow or elastic fibro- 
eartilage). 
In contrast with true bone, the analysis (by Fremy) of the calcified 
cartilage of the ray may be here given: — 
Ash per cent. . . . 3000 ( Jalcium carbonate . . 4 - 3 
Calcium phosphate . . 27 '7 Magnesium phosphate, traces. 
Tin matrix of hyalvru cartilage. — The organic basis of the matrix was 
formerly described as chondrigen] and just as gelatin is obtained from 
collagen on boiling, so chondrin is obtained by boiling chondrigen. 
Chondrin, like gelatin, gelatinises on cooling a solution of it made with 
warm water, but in many of its reactions it differs from gelatin. 
Elementary analyses of chondrin, however, showed very ureal, dis- 
crepancies, and Morochowetz 1 arrived at the conclusion that chondrin is 
not a chemical unit but a mixture of gelatin and mucin. This conclusion 
has been more recently amplified by C. T. Morner, 2 who worked under 
the superintendence of Hammarsten. 
The matrix contains four substances — (1) collagen, (2) an albuminoid, 
(3) chondromucoid, and (4) chondroitin-sulphuric acid. Of these con- 
stituents the last two, with perhaps a little collagen, lie around the cells, 
forming what Morner calls chondrin balls ; they correspond to the mucin 
of Morochowetz, or hyalogen of Krukenberg, and are coloured blue by 
methyl-violet. They lie in the meshes of a network composed of collagen 
and mucoid, which is stainable by tropaeolin. 
These four constituents may be separated as follows. The mucoid 
and chondroitin-sulphuric acid are dissolved out with 2 to 0'5 per 
cent, solution of potash ; the collagen is dissolved out by hot water, being 
converted into gelatin in the process; the albuminoid remains undissolved. 
(1) The collagen differs from ordinary collagen in only containing 
1G'4 per cent, of nitrogen. 
( 2 ) The album inoid, which is found only in late adult life, is a proteid- 
like substance of an insoluble nature. It contains loosely combined 
sulphur. It differs from elastin in its high percentage of sulphur (see p. 73). 
(3) Chondromucoid. — This substance has the following percentage 
composition :— C, 47*3 ; H, 642; X, 12-58; S, 2-42 : 0,31-28 (Morner). 
The sulphur is loosely combined. Chondromucoid gives the ordinary 
proteid reactions. On decomposition, it yields the usual decomposition 
products of proteids, with chondroitin-sulphuric acid in addition; this 
latter substance is, on further decomposition, broken up into sulphuric 
acid and a reducing substance. Schmiedeberg 3 regards chondromucoid 
as a union of proteid with chondroitin-sulphuric acid. 
(4) ( 'hondroitin-sulph uric axid. — This substance was called chondroitic 
acid by Bodeker 4 and Krukenberg 5 (who classed it among his hyaline, 
1 Verhwndl. d. naturh.-med. Ver. zu Heidelberg, Part 5, Bd. i. 
2 Ztsclir. f. physiol. Chem., Strassburg, Bd. xii. S. 396; Skandin. Arch. f. Physiol., 
Leipzig, Bd. i. S. 210. 
3 Arch. f. c.r/cr. Path. u. Pharmakol., Leipzig, 1891, Bd. xxviii. S. 355. 
4 Ann. d. Chem., Leipzig, 1661, Bd. cxvii. S. 111. 
8 Ztschr. f. Biol., Miinchen, Bd. xx. S. 307. 
