Chittenden and Hart — Elastin and the Elastose Bodies. 31 



Deuteroelastose. 



In the salt-saturated filtrates from protoelastose, deutero was sepa- 

 rated as a gummy, sticky precipitate by addition of a little 30 per 

 cent, salt-saturated acetic acid. It was purified by reprecipitation 

 and dialysis, and the final neutral solution was evaporated to dryness 

 and the residue dried at 110° C. until of constant weight. The 

 amount was small and only the nitrogen was determined, 16-88 per 

 cent. 



In reactions, the body closely resembled the deutero already de- 

 scribed ; its aqueous solution giving no precipitate or turbidity what- 

 ever on the application of heat, no precipitate with alcohol, or with 

 strong potassium hydroxide solution. It was likewise not precipi- 

 tated by acetic acid and potassium ferrocyanide, by the concentrated 

 or dilute mineral acids, nor by 30 per cent, acetic acid. In reactions, 

 the body resembles the elastin peptone of Horbaczewski, like it being- 

 soluble in cold and warm water and dilute alcohol, and giving the 

 same precipitations with phosphotungstic acid, picric acid, tannic 

 acid, and with potassium mercuric iodide. It also gives the biuret 

 and xanthoprotein reaction. It dilfuses slowly. 



With our present knowledge regarding peptones and proteoses, 

 this body can hardly be considered as belonging to the former class, 

 since it is precipitable both by ammonium sulphate, and by acetic 

 acid when added to a salt-saturated solution ; reactions not common 

 to true peptones. 



A second digestion of elastin A was made with the same quantities 

 of pepsin-hydrochloric acid, and the same amount of powdered elastin, 

 as in the first digestion. The products formed were separated in the 

 same manner as the preceding, the elastoses l)eing first precipitated 

 collectively by saturation of the digestive fluid with ammonium sul- 

 phate. 



On boiling the filtrate from this ammonium sulphate precipitate, a 

 second gummy mass separated. This was collected on a cloth filter 

 and washed with saturated ammonium sulphate solution. In the fil- 

 trate from this precipitate, no peptone could be detected. This 

 second ammonium sulphate precipitate was purified by dialysis, etc., 

 and the final solution evaporated to dryness and the substance dried 

 at 110° C. Its composition is shown in the accompanying table, 

 from which it is seen to be nearly identical with that of protoelastose. 

 The reactions, however, indicate that it is a mixture of the two elas- 

 toses. Thus, while the concentrated mineral acids and potassium 

 hydroxide give no precipitate, acetic acid and potassium ferrocyanide 



