v ALBUMOSES AND PEPTONES 177 



gastric digestion ; the chief investigators are Paal, 1 Sjoqvist, 2 Cohn- 

 heim, 3 Bugarszky and Liebermann, 4 Cohnheim and Krieger, 5 and 

 v. Rhorer. 6 Erb, 7 however, is the only observer who has worked with 

 a * pure ' albumose, 8 namely, hetero-albumose. The pure peptones pre- 

 pared by Siegfried 9 are distinctly acid; while the kyrins of Siegfried 10 

 are well-marked bases. Albumoses are still pluri-acid and pluri-basic ; 

 hetero-albumose is according to Erb 7 at least 23-acid; Siegfried's 9 

 peptones are monobasic if calculations are based on the simple 

 formula, but the results of dissociation by means of acids show that 

 the formula of these peptones must be multiplied. 



Albumoses have a smaller molecular weight than have the true 

 albumins, but it is still very high. If we make, for example, 

 deductions from the numbers obtained by analysis, primary albumoses 

 must possess at least a molecular weight of 2600, which weight must 

 probably be multiplied by 2, because of the cystin which contains 

 two atoms of sulphur. Because of their smaller size albumoses pass 

 through parchment, and they thus differ from the albumins, but 

 their passage is a very slow one. The different albumoses diffuse with 

 different velocities. 11 



Peptones possess a much lower molecular weight ; Siegfried 12 

 calculated originally the molecular weight for anti-peptone as 273, but 

 DOW 13 he believes this number to be too low ; pepsin-peptone diffuses, 

 according to Kiihne, 11 only one half as quickly as does grape-sugar. 



The question as to whether different albumins give rise to 

 different albumoses and peptones, or whether the same albumoses 

 and peptones, according to their arrangement, form different albumins, 

 is still an open one. In all probability the albumoses and peptones 

 differ as little from one another as do the amino-acids, for, with the 

 exception of casein, 14 and perhaps also of globin, 15 which do not contain 



I C. Paal, Ber. d. deutsch. diem. Ges. 25. I. 1202 (1892); ibid. 27. II. 1827 (1894). 

 a J. SjUqvist, Skandinav. Arch. f. Physiol. 5. 277 (1894). 



3 0. Cohnheim, Zeitschr. f. Biolog. 33. 489 (1896). 



4 St. Bugarszky and L. Liebermann, Pfliiger's Arch. f. d. ges. Physiol. 72. 51 (1898). 



5 0. Cohnheim and H. Krieger, Zeitschr. f. Biol. 4O. 95 (1900). 



6 L. v. Rhorer, Pfliiger's Arch.f. d. ges. Physiol. 90. 368 (1902). 



7 W. Erb, Zeitschr. f. Biol. 41. 309 (1901). 



8 See p. 184, where the results obtained by Haslam are discussed. 



9 M. Siegfried, Zeitschr. f. physiol. Chcm. 27. 335 (1899), 35. 164 (1902), 38. 

 259 (1903). 



10 M. Siegfried, Sitzungsber. d. sacks. Ges. d. Wissenschaften zu Leipzig, math.-phys. 

 KL, 1903, p. 63, 43- 44 and 46 (1904). 



II W. Kiihne, Zeitschr. f. Biol. 29. 1 (1892). 



12 M. Siegfried, Zeitschr. f. physiol. Chem. 35. 164 (1902). 



13 C. Borkel, ibid. 38. 294 (1903). 



14 F. Alexander, ibid. 25. 411 (1898), 15 F. N. Schulz, ibid, 24. 449 (1898). 



N 



