IX 



THE PHOSPHO-GLOBULINS 



397 



1. Caseinogen 1 



Caseinogen is the chief and most characteristic albumin of milk. 

 Because of its acid properties it was held for long to be an albuminate, 

 and was classed with the alkali-albuminates which are obtained by the- 

 denaturalisation of other albuminous substances. Hoppe-Seyler 2 and 

 then Hammarsteri 3 in particular taught us that caseinogen is a dis- 



tinct substance. 

 another. 4 



The caseinogens of different animals differ from one- 



Caseinogen of Cow's Milk 

 Analysis of cow's milk has given these percentage figures : 



The dissociation-products are given on p. 70, No. 7. The absence 

 of giycocoll and the carbohydrate radical and the high tyrosin- and 

 tryptophane- contents make caseinogen especially readily digestible 9 " 

 (see p. 148). For the same reason no hetero-albumose is formed 

 during peptic digestion. 9 



It is the only native albumin which is attacked by erepsin, 10 and 

 plays in ordinary metabolism a special part owing to its ready dis- 

 sociation. 11 In addition to tyrosin and tryptophane it also contains. 



1 The author has adopted Halliburton's nomenclature. The mother-substance is 

 called caseinogen ( = Kasein of the Germans), and the derived substance casein (=Para- 

 kasein of the Germans). 



2 F. Hoppe-Seyler, Vircfuno's Arch. 17. 417 (1859). 



:>> O. Hammarsten, auto-abstract after the Swedish original in Malys Jahresber. /. 

 Tierchemie, 2. 118 (1872); Konigl. Ges. d. Wissensch. zu Upsala, 1877 ; Zeitschr. f.. 

 physiol. Chem. 7- 227 (1883). 



4 A. Dogiel, ibid. 9. 591 (1885) ; Ellenberger, Arch.f. (Anat. nnd) Physiol. 1899,. 

 p. 33 ; 1902, Suppl. p. 313 ; F. Soxhlet, Munchener medizin. Wochenschr. 1893. 

 No. 4 ; A. Wroblewski, Dissertation, Bern, 1894 ; C. Storch, Monatsh. f. Chem. 23. 

 712 (1902). 



5 O. Hammarsten, Zeitschr. f. physiol. Chem. 7. 227 (1883) ; 9. 273 (1885). 



6 R. H. Chittenden and H. M. Painter, Studies frmn the Yale Univers. 2. 15fr 

 [according to Maly's Jahresber. /. Tierdiemie, 17. 16 (1887)]. 



7 W. Hempel, Pftilgers Arch. f. d. ges. Physiol. 56. 558 (1894). 

 s Ellenberger, Arch.f. (Anat. u.) Physiol. 1902, Suppl. p. 313. 



9 F. Alexander, Zeitschr. f. physiol. Chem. 25. 411 (1898). 



10 0. Cohnheim, ibid. 35. 134 (1902). 



11 W. Falta, Verh. der Naturforsch. Ges. in Basel. 15. Heft 2 (1903) ; Korre- 



