GASTRIC DIGESTION. 47 



precipitates are given by acetic acid and potassium ferro- 

 cyanide, acetic acid and sodium chloride or by nitric acid. 



Instead of using ammonium sulphate we may also precipitate the 

 albumoses from the acidified solution by means of sodium chloride. 

 For this purpose add to the 200 cc. of the solution obtained 10 cc. of 

 glacial acetic acid and grind the mixture with 75 g. of pure sodium 

 chloride. The separation takes place the same as it did when am- 

 monium sulphate was used : wash the albumoses with a concentrated 

 solution of sodium chloride. The sodium chloride is removed by 

 dialysis. After the dialysis concentrate the solution and precipitate 

 with alcohol. We may also purify the precipitate by dissolving it 

 in water, heating the solution, adding a solution of salt until the hot 

 fluid is no longer clear, cooling and purifying the precipitate thus 

 obtained by dialysis. The precipitation of the albumose by acetic 

 acid and salt is not so complete as that with ammonium sulphate. 

 The peptone remaining in solution therefore contains albumose. 



According to S. Frankel 1 albumose and peptone may be separated 

 from each other by means of alcohol alone. 



1 Wiener, med. Blatter, 1896, Nos. 45 and 46. 



