196 THE PRODUCTS OF ALBUMINOUS DIGESTION. 



be present, as well as primary albumoses, are removed as just de- 

 scribed. 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 is effected, and on standing the 

 deutero-fraction A separates out ; this is filtered off and the solution 

 saturated with ammonium sulphate in substance. As a result the 

 deutero-fraction 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 sulphate, and of which 10 c.c. cor- 

 respond in strength to 17 c.c. of a one-tenth normal solution of 

 sodium hydrate, the deutero-albumose-C finally separates out on 

 standing. The resulting filtrate is free from albumoses and should 

 contain the amphopeptone of Kiihne. Two additional fractions can 

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

 potassic iodide (containing 2 parts of the iodide to 1 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 (Pick) passes into 

 solution, while peptone- A (Pick) remains undissolved. This portion 

 is dissolved in a little warm water, the solution saturated with am- 

 monium 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. Pep- 

 tone-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. 



THE PRODUCTS OF TRYPTIC DIGESTION. 



One hundred grammes of moist fibrin, as in the above experi- 

 ment, are placed in a liter of an 0.25 per cent, solution of sodium 

 carbonate, to which a few grammes of commercial pancreatin have 

 been added. Putrefaction is guarded against by the addition of 

 chloroform and thymol. The mixture is kept at a temperature of 

 40 C., and can be examined after twenty-four to thirty-six hours. 

 For the preparation of antipeptone, however, in amounts which can 

 be utilized to demonstrate the presence of the diami no-acid, it is 

 necessary to take a much larger quantity of fibrin and to extend the 

 period of digestion over several weeks. From 1410 grammes 

 Kutscher claims to have obtained 200 grammes. 



The filtered fluid is first neutralized with dilute sulphuric acid, 

 which causes the separation of any alkaline albuminate that may be 

 present. Coagulable albumins are removed by acidifying the solu- 

 tion with acetic acid and boiling. The solution is then treated with 

 one and one-half times its volume of a saturated solution of ammo- 

 nium sulphate. On standing, the deutero-fraction A separates out. 

 On complete saturation with the salt in substance the deutero- 

 fraction B is obtained ; a C-albumose is not formed on tryptic diges- 



