406 



CHEMISTRY OF THE PROTEIDS 



CHAP. 



so-called * yolk - platelets.' l It has cost much labour to prepare 

 ichthulin in a pure form. Hoppe-Seyler believes ichthulin to be a 

 lecith - albumin. Walter 2 has examined the eggs of the carp and 

 Levene 3 those of the cod. 



The carp -ichthulin contains a reducing substance, but, like all 

 nucleo-albumins, no xanthin-bases ; it only dissolves into a clear solu- 

 tion in the presence of alkalies, while to salt-solutions it imparts an 

 opalescence. From such salt-solutions it is precipitated by diluting 

 the salt-solution or by passing carbon dioxide through the solution. 



4. Cell-Nucleo-Albumins 



In the plasma forming the body of the cell, or the cytoplasma, are 

 found, in addition to the globulins, and substances belonging to the 

 myosin - group, constantly also iron - containing nucleo - albumins. 

 These latter have been investigated by Halliburton, 4 Lilienfeld, 5 

 Hammarsten, 6 and Lonnberg, 7 a pupil of Hammarsten. 



The cell -nucleo -albumins give the ordinary reactions of the 

 nucleo-albumins, i.e. their salts are readily soluble, while they them- 

 selves are only slightly, or not at all, soluble in pure water ; in dilute 

 salt - solutions they are more readily soluble. Some of the sub- 

 stances isolated formerly by Halliburton may be nucleo - proteids 

 derived from the cell-nuclei. From the nucleo-proteid of the liver of 

 the snail Hammarsten isolated a carbohydrate. The nucleo-albumiri 



1 M. Gobley, Journ. de Pharm. et de Chim. 3rd ser. 17. 401 (1850 ; A. 

 Valenciennes and E. Fremy, Oompt. rend. 38. 471 (1854) ; F. Hoppe-Seyler, Medizin- 

 chem. Unters. pp. 215, 221 (1868) ; F. N. Schulz, Kristallis. von Eiweiss. Jena, 1891. 



2 G. Walter, Zeitschr. f. physiol. Chem. 15. 477 (1891). 



3 P. A. Levene, ibid. 32. 281 (1901). 



4 W. D. Halliburton, 'The Proteids of Kidney and Liver Cells,' Journ. of Physiol. 

 13. 896 (1892) ; 9. 229 (1888) ; 'Proteids of Nervous Tissues,' ibid. 15. 90 (1894) ; 

 Halliburton and Gregor Brodie, ' Nucleo-Albumins and Intravasc. Coagul.' ibid. 17. 

 135 (1894); Forrest, 'Bed Marrow,' ibid. 17- 174 (1894); F. Gourlay, 'Thyroid and 

 Spleen,' ibid. 16. 23 (1894). 



5 L. Lilienfeld, Zeitschr. f. physiol. Chem. 18. 473 (1893). 



6 0. Hammarsten, 'Studies on Mucin,' etc., Pfluger's Arch. 36. 373 (1885). 



7 Ingolf Lounberg, Skandiv. Arch. f. Physiol. 3. 1 (1890). 



