TISSUES OF THE CONNECTIVE SUBSTANCE. 235 



boiling with acids it yields acid albuminate, peptone substance, 

 chondroitic 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 quantities of mineral acids. The precipitation 

 may be retarded by neutral salts or by chondroitic acid. The 

 solution containing NaCl and acidified with HC1 is not precipitated 

 by potassium ferrocyanide. Precipitants for chondromucoid are 

 alum, ferric chloride, sugar of lead or basic lead acetate. Chon- 

 dromucoid is not precipitated by tannic acid, and it may by its 

 presence prevent the precipitation of gelatine by this acid. It gives 

 the usual color reactions for albuminous bodies; namely, with 

 nitric acid, with copper sulphate and alkali, with MILLON'S and 

 ADAMKIEWICZ'S reagents. 



Chondroitic Acid. This acid, which thus far has not been ob- 

 tained free, but as acid salts, has, according to MORNEB. the follow- 

 ing composition : C 35.28, H 4.68, N 3.15, S 6.33, 50.56 per cent. 

 On boiling with dilute hydrochloric acid all the sulphur splits off as 

 H 2 S0 4 , and a reducing substance is formed at the same time whose 

 nature is not known. 



This acid (more correctly the acid alkali salts) 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. The neutralized 

 solution is precipitated by tin 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 acid, sugar of lead, 

 mercuric chloride, or silver nitrate. Chondroitic acid does not give 

 the color reactions for albuminous bodies. 



Preparation of chondromucoid and chondroitic acid. If very 

 finely-cut cartilage is extracted with water, the preformed chon- 

 droitic acid, as well as some chondromucoid, is dissolved. In this 

 watery extract the chondroitic acid prevents the precipitation of 

 this chrodromucoid by means of an acid. If 2-4 p. m. 1 

 added to this watery extract and warmed on the water-bath, the 



