362 THE LIVER. 



cipitates produced by little acid, in an excess of acid, and in neutral salts 

 seem to indicate that we here have a mixture which consists chiefly of 

 nucleoproteins and not of globulins. The nearly complete digestibility 

 with pepsin-hydrochloric acid does not controvert this assumption, 

 because, as is known, nucleoproteins may on digestion yield no residue 

 (see Chapter III). Nor can we be positive concerning the nature 

 of the liver-globulin found by DASTRE,* having a coagulation tem- 

 perature of 56. The proteins extractable from the liver without modifi- 

 cation must be thoroughly investigated. 



Besides the above-mentioned proteins, which are very soluble, the 

 liver-cells contain large quantities of difficultly soluble protein bodies 

 (see PLOSZ). The liver also contains, as first shown by ST. ZALESKI 

 and later substantiated by several other investigators, ferruginous 

 proteins of different kinds. 2 The chief portion of the protein substances 

 in the liver seems in fact to consist of ferruginous nucleoproteins. On 

 boiling the liver with water, such a nucleoprotein or perhaps several 

 are split, and a solution is obtained containing a nucleic-acid-rich nucleo- 

 protein or a mixture of these which are precipitable by acids. This 

 protein or protein mixture, which has been called ferratin by SCHMIE DE- 

 BERG, 3 has been studied by WoHLGEMUTH. 4 The quantity of phos- 

 phorus was 3.06 per cent. As cleavage products on hydrolysis he 

 found Z-xylose, the four nuclein bases, and also arginine, lysine (and 

 histidine?), tyrosine, leucine, glycocoll, alanine, a-proline, glutamic acid, 

 aspartic acid, phenylalanine, oxyaminosuberic acid, and oxydiamino- 

 sebacic acid (see Chapter III) . The Z-xylose depends, no doubt, at least 

 in part, upon the guanylic acid isolated from the liver, by LEVENE 

 and MANDELA and the finding of adenine among the cleavage products 

 also indicates the presence of a thymonucJeic acid. There does not 

 seem to be any doubt that the ferratin, as above stated, is a mixture, 

 and the correctness of this assumption is shown by the recent investiga- 

 tions of SCHAFFIDI and SALKOWSKI. 6 



The yellow or brown pigment of the liver has been little studied. DASTRE 

 and FLORESCO 7 differentiate, in vertebrates and certain invertebrates, between a 



1 Pohl, Hofmeister's Beitrage, 7; Dastre, Compt. rend. soc. biolog., 58. 



2 St. Zaleski, Zeitschr. f. physiol. Chem., 10, 486; Weltering, ibid., 21; Spitzer, 

 Pfluger's Arch., 67. 



3 Arch. f. exp. Path. u. Pharm., 33; see also Vay, Zeitschr. f. physiol. Chem., 20. 



4 Wohlgemuth, Zeitschr. f. physiol. Chem., 37, 42, and 44, and Ber. d. d. chem. 

 Gesellsch., 37. See on liver nucleoproteins also Salkowski, Berl. klin. Wochenschr., 

 1895; Hammarsten, Zeitschr. f. physiol. Chem., 19; Blumenthal, Zeitschr. f. klin. Med., 

 34. 



5 Bioch. Zeitschr., 10. 



6 Schaffidi, Zeitschr. f. physiol. Chem., 58; Salkowski, ibid., 58. 



7 Arch, de Physiol. (5), 10. 



