348 



RETROGRESSIVE PROCESSES 



Chondroitin-sulphuric acid, which has been studied especially by 

 Morner and by Schmiedeberg, l has the formula C 18 H 27 NSO 17 , according 

 to the latter, and yields on cleavage chondroitin and sulphuric acid, as 

 follows : 



C 18 H 27 NS0 17 + H 2 == C 18 H 27 N0 14 + H 2 SO 4 . 



(chondroitin) 



Chondroitin is a gummy substance which in turn may be split into acetic 

 acid and a reducing substance, chondrosin. Chondroitin-sulphuric acid 

 is the characteristic component of cartilage, but it is also found in mucin 

 (Levene), and in the walls of the aorta and other elastic structures 

 (Krawkow). It has also been found in a uterine fibroma and in bone 

 tissue by Krawkow, but could not be found in the parenchymatous 

 organs, normal and pathological, or in chitinous structures. Morner 

 has also found it in a chondroma. 



Chemistry of Amyloid. Krawkow separated amyloid 

 from nucleoproteid, to which it is most closely related, by dis- 

 solving both substances from the minced amyloid organs with 

 ammonia, precipitating with acid, and then taking up the amyloid 

 with Ba(OH) 2 solution, in which the nucleoproteid does not dis- 

 solve. Amyloid thus isolated is a nearly white powder, which 

 is easily soluble in alkalies, but slightly in acids, and is very 

 resistant to pepsin digestion. The elementary composition was 

 found by Krawkow to be approximately as follows : 



C = 49-50$; H = 6.65-7$; N= 13.8-14$; 8 = 2.65-2.9$; P in traces only. 



Quite similar analytic results have been obtained by Neu- 

 berg, 2 who corroborated Krawkow's finding of a body of ap- 

 parently similar composition in the normal aorta. Neuberg has 

 studied especially the proteid constituent of the amyloid com- 

 pound, and found it characterized by a high proportion of diam- 

 ino-nitrogen, as compared with most proteids, as shown in the 

 following table giving the percentage of the total N contained in 

 each of the three forms, amid-nitrogen (ammonia), monamino- 

 acids, and diamino-acids : 



TABLE I. 



1 . Morner, Skand. Arch. Physiol., 1889 (1), 210; Zeit. physiol. Chem., 1895 

 (20), 357, and 1897 (23), 311 ; Schmiedeberg, Arch. exp. Path. u. Pharm., 

 1891 (28), 358. 



2 Verb. Dent. Path. Gesell., 1904 (7), 19. 



