THE GELATIN FROM WHITE FIBROUS 

 CONNECTIVE TISSUE.* 



BT WILLAED G. VAN NAME. 



IN a general way the chemical nature and composition of 

 gelatin have been established for many years, but the more 

 thorough chemical study of various forms of connective tissue, 

 which has been carried on so successfully during the last 

 decade, has revealed the existence of at least three distinct 

 varieties of collagen, characterized by marked differences in 

 chemical composition. The collagen of white fibrous tissue 

 and of bone is generally considered as the same ; it apparently 

 yields on hydration a gelatin with about 18 per cent of nitrogen. 

 The collagen which makes up the greater portion of the 

 cornea, on the other hand, contains about 17 per cent of 

 nitrogen, f while the collagen of cartilage J yields a gelatin 

 with only 16 per cent of nitrogen. Furthermore, we have 

 evidence of the existence of a body in reticular tissue 

 reticulin the composition of which appears to lie midway 

 between that of gelatin and of elastin. Its nitrogen-content, 

 according to Siegfried, is 15.63 per cent. Again, the amount 

 of sulphur in gelatin is usually placed at about 0.6 per cent,|| 

 but the gelatin formed from corneal collagen contains only 

 0.3 per cent of this element.^" Lastly, Schiitzenberger and 

 Burgeois consider gelatin (commercial gelatin) as practically 



* Eeprinted from the Journal of Experimental Medicine, vol. ii. 



t Morner, Untersuchung der Proteinsubstanzen in den lichtbrechenden 

 Medien des Auges. Zeitschr. f. physiol. Chem., Bd. xviii, p. 224. 



J Morner, Studien iiber die Chemie des Trachealknorpels. Jahresbericht 

 d. Thierchemie, 1888, p. 220. 



Siegfried, Ueber die chemischen Eigenschaften des rcticulirten Gewebes. 

 Habilitationsschrift, Leipzig, 1892. 



|| Hammursten's Lehrbuch d. physiolog. Chem., 1895, p. 46. 



7 Morner, Zeitschr. f. physiol. Chem., Bd. xviii, p. 225. 



