THE PRODUCTS OF TRYPTIC DIGESTION. 185 



The general reactions of the various albumoses and the two pep- 

 tone fractions which can thus be obtained from fibrin are shown in 

 the accompanying table (pages 186 and 187). But while the albu- 

 moses, of Whatever origin, apparently behave toward ammonium 

 .sulphate in the same manner, some of these at least differ from the 

 ,fibri noses in other respects. The deviations, however, are on the 

 -whole but slight, and may well be disregarded at this place. 



THE PRODUCTS OF TRYPTIC DIGESTION. 



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

 ments, 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 anti peptone, however, in amounts which 

 can be utilized to demonstrate the presence of the hexon bases, 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 as much as 200 grammes, but I 

 have personally not been so successful. 



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-albumose-A. separates out. 

 On complete saturation with the salt in substance the deutero- 

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

 digestion. On acidifying with sulphuric acid, however, as in the 

 .-study of peptic digestion, it may happen that a turbidity appears, 

 which is probably due to the presence of Neumeister's antideutero- 

 .albumose. The final filtrate then contains the common amido- 

 .acids, antipeptone, tryptophan, and probably other substances also 

 which are as yet but imperfectly known. 



Leucin. Aside from its formation during the process of pancreatic 

 digestion or on artificial decomposition of albumin with dilute mineral 

 acids and alkalies, leucin has been demonstrated in the spleen, in the 

 lymph-glands, in the thyroid, the kidneys, the liver, and the brain, 

 though mostly under pathological conditions, when it may also 

 appear in the urine. It is further found in sheep's wool, in decom- 

 posing epithelial structures, as in the desquamated material which is 

 found between the toes, etc. Its presence in the intestine may also 

 be due to the action of bacteria upon the albuminous products of 

 digestion. 



In pure form leucin crystallizes in extremely thin white lustrous 

 platelets : but more commonly it is seen in the form of spherules of 



