548 TISSUES OF THE CONNECTIVE SUBSTANCE. 



more strongly than glucose. It is dextrogyrate, and represents the 

 reducing substance obtained by previous investigators in an impure 

 form on boiling cartilage with an acid. The products obtained on decom- 

 posing chondrosin with barium hydroxide tend to show, according to 

 SCHMIEDEBERG, that chondrosin contains the atomic groups of glucuronic 

 acid and glucosamine. This assumption does not seem to have sufficient 

 foundation. According to ORGLER and NEUBERG, chondrosin does not 

 give the orcin test nor does it yield furfurol. They claim that on 

 cleavage with baryta it yields, besides a carbohydrate complex which 

 has not been studied, an oxyamino-acid having the formula CeHisOeN, 

 a hexosamine acid or tetraoxyaminocaproic acid. In opposition to this 

 S. FRANKEL has found that the chondrosin gives the orcin as well as the 

 phloroglucin test with hydrochloric acid, and he has prepared an acid 

 with the formula CeHnNOe, which he calls aminoglucuronic acid, 

 which gives the above tests and also reduces. Among other investi- 

 gators, PONS and KONDO 1 have also found that chondroitin-sulphuric 

 acid gives the orcin test and yields furfurol, according to PONS 6.6-6.9 

 per cent. The chondrosin obtained after boiling with acid and distilling 

 off the furfurol does not, according to PONS, give furfurol, which agrees 

 with ORGLER and NEUBERG'S statement. From the hydrolytic products 

 of chondroitin-sulphuric acid with hydrochloric acid, PONS obtained 

 with phenylhydrazin a crystalline substance melting at 143 C. 



Chondroitin-sulphuric acid appears as a white amorphous powder 

 which dissolves very easily in water, forming an acid solution and, when 

 sufficiently concentrated, a sticky liquid similar to a solution of gum 

 arabic. Nearly all of its salts are soluble in water. The neutralized 

 solution is precipitated by stannous chloride, basic lead acetate, neutral 

 ferric chloride, and by alcohol in the presence of a little neutral salt. 

 The solution, on the other hand, is not precipitated by acetic acid, 

 tannic acid, potassium ferrocyanide and acetic acid, sugar of lead, mer- 

 curic chloride, or silver nitrate. Acidified solutions of alkali chondroitin- 

 sulphates cause a precipitation when added to solutions of gelatin or 

 proteid. 



. The preparation of chondromucoid, and its separation from chondroitin- 

 sulphuric acid can be accomplished after the method of C. MORNER, but for 

 details we refer to the original work. 



The pre-existing chondroitin-sulphuric acid, or that formed by the 

 decomposition of chondromucoid, is obtained by lixiviating the cartilage 

 with a 5-per cent caustic-alkali solution. The alkali albuminate formed 

 by the decomposition of the chondromucoid can be removed from the 

 solution by neutralization, then the peptone precipitated by tannic acid, 



1 Orgler and Neuberg, Zeitschr. f. physiol. Chem., 37; Frankel, Annal. d. Chem. u. 

 Pharm., 351; Pons. Arch, intern, de Physiol., 8 (1909); Kondo, Bioch. Zeitsphr., 26. 



