184 THE PRODUCTS OF ALBUMINOUS DIGESTION. 



The further steps in the digestion of fibrin may be studied in a 

 specimen which has been kept at a temperature of 40 C. for two 

 to three weeks. Syntonin or native soluble albumin that may still 

 be present, as well as the primary albumoses, are removed as just 

 described. The neutral solution is then treated with one-half its 

 volume of a saturated solution of ammonium sulphate. In this 

 manner a two-thirds saturation of the solution is effected, and on 

 standing the deutero-albumose-A separates out. This is filtered 

 off, and the solution saturated with ammonium sulphate in sub- 

 stance. As a result the deutero-albumose-B' is thrown down, and 

 on acidifying the filtrate with one-tenth its volume of a solution 

 of sulphuric acid that has been saturated with ammonium sul- 

 phate, and of which 10 c.c correspond in strength to 17 c.c. of 

 a one-tenth normal solution of sodium hydrate, the deutero-albu- 

 mose-C finally separates out on standing. The resulting filtrate is 

 then free from albumoses, and should contain the amphopcptone of 

 Kuhne. But, as I have indicated, two additional fractions can be 

 obtained from the final solution. To this end, a solution of iodo- 

 potassic iodide, containing two parts of the iodide to one part of 

 iodine, which has been saturated with ammonium sulphate, is added 

 until precipitation is complete. The material which is thus thrown 

 down is placed in 96 per cent, alcohol. Peptone-B then passes into 

 solution, while peptone-A remains undissolved. This portion is dis- 

 solved in a little warm water, the solution saturated with ammonium 

 sulphate, and reprecipitated with the iodine solution. The peptone 

 is then redissolved in warm water, reprecipitated with alcohol, and 

 freed from any remaining iodine by shaking with ether. Peptone-B, 

 on the other hand, is obtained by evaporating its alcoholic solution 

 to dryness, when the residue is dissolved in water and freed from 

 iodine by shaking with ether. 



Pick's deutero-albumose-B, which, in contradistinction to the 

 B'-albumose, is said to contain carbohydrate groups, has not as yet 

 been accounted for in the above analytical schema. This is owing 

 to the fact that Pick has not indicated the exact manner in which 

 the substance can be isolated. In his latest publication he merely 

 states that on careful purification of the deutero-albumoses which 

 can be obtained from Witte's peptone (this is largely a mixture 

 of albumoses derived from fibrin) it was noted that the deutero- 

 albumose-B showed in gradually increasing degree the existence of 

 carbohydrate radicles, while A and C in pure form were free from 

 these groups. But, as we have seen, both the proto- and the hetero- 

 albumose on further digestion yield a deutero-albumose-B 7 which 

 manifestly contains no carbohydrate groups. It is possible that the 

 B-albumose is hence precipitated together with the B'-albumose; but 

 if it is found in this fraction, it should be possible to isolate the 

 substance in the earlier stages of digestion already, as it is stated 

 that its formation coincides in point of time with that of Kuhne's 

 primary albumoses. 



