

NERVOUS TISSUES. 



see p. 64). It was first prepared in a pure condition by Morner, and 

 its constitution made out by that observer and by Schrniedeberg. It is 

 partly found as such in the cartilaginous matrix, but most originates 

 from the decomposition of chondromucoid. 



Morner found that the sulphur in it was all in the form of ethereal 

 hydrogen sulphate ; hence the name chondroitin-sulphuric acid. It is 

 almost, but not quite, characteristic of cartilage. Morner l separated it 

 from twenty different varieties of cartilage, from cartilaginous tumours, 

 and also from the tunica intiina of the aorta, 2 but from no other tissue 

 or organ of the body. 3 



Schmiedeberg ascribes to it the formula C 18 H 27 NS0 17 . On decom- 

 position, the first products are sulphuric acid, and a nitrogenous sub- 

 stance chondroitin. 



C 18 H 27 NS0 17 +H 2 - H 2 SO f +C J 



(chondroitin-sul- (water) (sulphuric (chondroitin) 

 phuricacid) acid) 



Chondroitin is a gummy material, and a monobasic acid. On 

 hydration it yields acetic acid, and a new nitrogenous body called 

 chondrosin. 



C 18 H 2T NO H +3H. 2 - C 2 H 4 2 +C 12 H 21 NO n 



(chondroitin) (water) (acetic acid) (chondrosin) 



Chondrosin is also gummy, and a monobasic acid. It reduces 

 Fehling's solution even more strongly than dextrose; it is dextro- 

 rotatory, and is the reducing substance which so many previous chemists 

 have obtained in an impure form from cartilage. On further decomposi- 

 tion it yields glycuronic acid (see p. 5) and glucosamine (see pp. 9 and 75). 



NERVOUS TISSUES. 



General composition. The amount of water varies. It is present 

 in larger amount in the grey than in the white matter, in early 

 than in adult life, in the brain than in the spinal cord, in the spinal 

 cord than in nerves. These facts are illustrated by the following 

 table 4 : 



1 Ztschr. f. physiol. Chem., Strassburg, 1895, Bd. xx. S. 357. 



2 Upsala Lakarsf. Forh. , Bd. xxix. 



3 Oddi (Arch. f. exper. Path. u. PharmahoL, Leipzig, Bd. xxxiii.) states he has obtained 

 it from livers which had undergone amyloid degeneration. 



4 In the above table, ( W.) refers to Weisbach (Hofmann's "Lehrbuchd. Zoochemie," Wien 

 1876, S. 121); (B.) to Bernhart (Gamgee's "Physiol. Chem.," vol. i. p. 446); (P.) to 

 Petrowsky (Arch. f. d. gcs. Physiol., Bonn, Bd. vii.' S. 367) ; (M.) to Moleschott (Charles, 

 "Physiol. Chem.," p. 335); and (R.) to de Regibus (Jahresb. it. d. Fortschr. d. Thier- 

 Chem., Wiesbaden, Bd. xiv. S. 346). 



