x THE GLYCO-PROTEIDS : CHONDRO-SULPHURIC ACID 545 



3. Give a reducing substance after having been boiled with 

 hydrochloric acid. 



4. Give sulphur-reactions. 



Morner, 1 adopting these tests, was able to demonstrate the 

 presence of chondro-sulphuric acid in all varieties of cartilage, in 

 enchondromata, and in the inner layers of the aorta ; Lonnberg 2 

 found it in the skate (Raja batis) ; traces of it were also found by 

 Morner 3 and Krawkow 4 in bones, by Krawkow in the ligamentum 

 nuchae and in the gastric mucous membrane of the pig. It would 

 appear to also occur in the mucoid of tendons and bones (see above). 

 Levene 5 states to have discovered a similar substance in the spleen. 



Large amounts were found by Schmiedeberg's pupils Oddi 6 and 

 Krawkow 4 in 'amyloid' (see p. 574), but in this substance it seems to 

 be more firmly united than in chondro-mucoid. According to Krawkow, 

 chondro-sulphuric acid is the cause of amyloid staining with methyl 

 violet. If sodium chondro- sulphate be administered in the food it i& 

 excreted in large amounts by the kidneys ; traces are also found in 

 the liver. K. Morner 7 has finally found chondro-sulphuric acid 

 regularly and in not inconsiderable quantities about 0'05 per cent 

 in normal urine. This observation is important, because if albumin be 

 present, chondro-sulphuric acid will precipitate it whenever the urine 

 is acidified, and, on the other hand, some albumin-reactions, as, for 

 example, precipitation with tannic acid, will be prevented by it. A 

 certain percentage of the ethereal sulphuric acids belongs, therefore, 

 to chondro-sulphuric acid and not to indoxyl-sulphuric acid, etc. 



To prepare chondro-sulphuric acid Morner proceeds as follows r 

 The cartilage is divided into small pieces, and is then extracted for 

 several days at room temperature with 2 to 5 per cent caustic potash. 

 This extract contains, in addition to chondro-sulphuric acid, an 

 albuminate and the albumoses of the mucoid, a little collagen and 

 albumoid. To remove the albuminate the solution is first neutralised 

 and then rendered slightly acid with acetic or hydrochloric acid ; the 

 other albuminous substances are then removed with tannic acid, first 

 in acid and then in slightly alkaline solutions ; the tannic acid is 

 precipitated from the slightly acid solution with lead acetate ; the lead 



1 C. T. Morner, Zeitschr.f. physiol. Chem. 20. 357 (1894). 



2 J. Limnberg, Hammarsten's abstract from the Swedish original in Malys Jahres- 

 ber.f. Tierchem. 19. 325 (1889). 



3 C. T. Morner, Zeitschr. f. physiol. Chem. 23. 311 (1897). 



4 N. P. Krawkow, Schmiedeberg's Arch.f. exper. Path. u. Pkarm. 4O. 195 (1897). 



5 P. A. Leveue, Zeitschr. f. physiol. Chem. 37. 400 (1903). 



6 Ruggero Oddi, Schmiedeberg's Arch. f. exper. Path. u. Pharm. 33. 376 (1893). 



7 K. A. H. Morner, Skandinav. Arch. f. Physiol. 6. 332 (1895). 



2 N 



