Chittenden and Hart — Elastm and the Elastose Bodies. 23 



Elastin A., prepared by the usual process, shows a close agreement 

 in composition with Horbaczewski's product, but is quite different 

 from the product obtained by Miiller and Tilanus, as seen from the 

 following table. 



Elastin A. Horhaczeivski. Miiller* Tilanus* 



C 54-24 54-32 55-09-55-72 54-90-55-65 



H 7-27 6-99 7-11-7-67 7-25-7-41 



N 16-70 16-75 15-71-16-52 17-52-17-74 



The liigher content of carbon in the preparations of Miiller and 

 Tilanus are doubtless due to the presence of more or less fat, not 

 completely extracted by ether. 



Decomposition of Elastin by acid loater at 100" C. 



On heating moist elastin with water containing a trace of hydro- 

 chloric acid, for some hours at or near 100° C. it soon commences to 

 swell, and after a time becomes converted into a semi-gelatinous 

 mass, a portion of which, as the boiling continues, becomes soluble and 

 passes into the acid fluid. The liquid gives no reaction with tannic 

 acid for gelatin, but does give a strong biuret reaction and yields a 

 heavy turbidity when excess of strong potassium hydroxide is added 

 to the solution. Evidently, under these conditions, some soluble 

 cleavage product or products are formed, percipitable by excess of 

 caustic alkali. 



These products we prepared in quantity by taking a portion of elas- 

 tin ^, soaking it for some time in 5 per cent, hydrochloric acid, until 

 the softened elastin was thoroughly impregnated with the acid, then 

 washing out the excess of acid by soaking it for 20 hours in a laro-e 

 volume of water. The elastin, still quite strongly acid to test papers, 

 was then boiled in water for about 10 hours, when the acid liquid 

 was strained off from the gelatinous elastin. The boiling was then 

 continued with a fresh volume of water, the gelatinous mass still 

 containing sufficient acid to render the whole fluid distinctly acid 

 to test papers. Tnis process was repeated until the elastin had 

 been heated for 45 hours with water gradually containing less 

 and less acid, until finally the elastin remaining had entirely lost 

 its former gelatinous appearance and taken on its original look. 

 All of the acid fluids were united and concentrated somewhat, 



* Gorup-Besanez, Physiologische Cliemie, Dritte Auflage, p. 148 



