v ACID-ALBUMOSES AND PEPTONES 199 



Vines, 1 Emmerling, 2 and Siegfried. 3 The authors agree that papa- 

 yotin is active whatever the reaction may be ; Mendel found it to be 

 most active in alkaline, and Vines in acid media. According to Mendel 

 it forms the same albumoses as does pepsin according to Pick, while 

 Siegfried says the peptones are acid peptones, somewhat resembling 

 those obtained by peptic and by tryptic digestion. Whether it forms 

 crystalline dissociation-products has not yet been settled. Mendel 

 failed to find them, Vines found tryptophane, and Emmerling amino- 

 acids, but in very minute quantities. The main bulk of the dissocia- 

 tion-products consists of albumoses and peptones. According to 

 Kurajeff and Ingraham it produces in solutions of albumoses a pre- 

 cipitate, as do other proteolytic ferments. 



Bromelin, precipitated from pine-apple juice with sodium-chloride 

 requires 0.025 per cent HC1 and 0.25 to 1 per cent acetic acid to 

 develop its maximal digestive power (Hoyer). 4 



Antweiler's peptone 5 consists of meat digested with papayotin. 



IV. ALBUMOSES AND PEPTONES PRODUCED BY ACTION OF 



ACIDS 



When albumins are boiled with strong acids there are formed 

 amino-acids, but if one allow dilute T V or J-normal hydrochloric or 

 sulphuric acids to act at room- or at incubation-temperature on albumins, 

 according to Goldschmidt, 6 exactly the same albumose- and peptone- 

 fractions are obtained as after peptic digestion. Goldschmidt examined 

 egg-albumin and crystallised serum-albumin ; Pick and Spiro, 7 edestin 

 and casein. Acid -albumin is formed first, but it soon breaks up into 

 primary albumoses, deutero-albumoses, and peptones. Serum-albumin, 

 which is readily digested by pepsin, was found to be attacked with 

 great difficulty ; the same holds good for edestin. After 0'8 per cent 

 hydrochloric acid had acted for eight days, 90 per cent of acid- 

 albumin was still present. 



Langstein and Neuberg on the other hand find that weak acids 

 have no effect on albumin, for Langstein 8 remarks : "1 per cent 

 H 2 S0 4 at 37 will not dissolve, even after months, crystallised egg- 



1 S. H. Vines, Annals of Botany, 17. 597 (1903). 



2 Emmerling, Ber. d. deutsch. chem. Ges. 35. I. 695 (1902). 



3 M. Siegfried (and Tittmann), Zeitschr. fur physiol. Chem. 38. 259 (1903). 



4 Hoyer, Ber. d. deutsch. chem. Ges. 37. 1436 (1904). 



5 J. Munk, Therapeutische Monatshefte, 1888, p. 176 ; R. Neumeister, Zeitschr. f. 

 Biol. 26. 57 (1890). 



6 F. Goldschmidt, Medizinische Dissertation, Strassburg, 1898. 



7 E. P. Pick and K. Spiro, Zeitschr. f. physiol. Chem. 31. '251 (1900). 



8 L. Langstein, ibid. 31. 208 (1900). 



