ix THE PHOSPHO-GLOBULINS 407 



of the kidney, that of the lymph-corpuscles and of the liver of the 

 snail, form with concentrated salt - solutions a mucilaginous jelly, 

 while according to Halliburton the nucleo -albumin prepared from 

 mammalian liver does not show this peculiarity. The colour-reactions 

 are those common to other albumins ; the biuret-test gives a violet 

 colour. They are only completely precipitated by sodium chloride 

 sulphate if the solutions are saturated; ammonium and magnesium 

 sulphate precipitates in half-saturated solutions, but the exact pre- 

 cipitation-limits have not yet been worked out. 



The coagulation - temperatures for the nucleo - albumins of the 

 kidney Halliburton found to be 63, and from 56 to 60 for those of 

 the liver and many other organs. 



The nucleo - albumins of the snail's liver and of the leucocytes 

 have been completely analysed, and those of the kidney and 

 mammalian liver partially. 



5. Nucleo-Albumins resembling Mucin 



It is difficult to draw a line of demarcation between these sub- 

 stances and those described above. As regards their physical pro- 

 perties they behave like the typical mucins and mucoids, for with 

 neutral ammonium or alkali-salts they form viscous solutions which 

 may be drawn out into threads ; they are precipitated by acids. 

 When they are denaturalised by too strong or too prolonged action of 

 alkalies, by prolonged boiling, or treatment with alcohol, they lose 

 their mucinoid character. It is not possible to coagulate them. 



Our knowledge regarding these substances we owe to Hammarsten l 

 and to his pupils Paijkull 2 and Lonnberg, 3 for they showed that the 

 mucinoid substance which is excreted by the kidney, the gall-bladder, 

 and the sy no vial membranes of the ox is not a mucin but a nucleo- 

 albumin. The urin of the ox also contains only a mucinoid nucleo- 

 albumin, while the bile of man and dog 4 contains a true mucin. 

 Salkowski 5 has found in the fluid which accumulates during coxitis 

 in the human hip -joint, in addition to the nucleo-albumin also a 

 mucin or mucoid. 



All these substances contain a fairly high percentage of sulphur, 



1 0. Hammarsten, ' Chemistry of the Synovia, ' auto-abstract in Malys Jahresber. f. 

 Tierchem. 12. 480 (1882). 



2 L. Paijkull, 'The Mucus of the Bile,' Zeitschr. f. physiol. Chem. 12. 196 (1887). 



3 J. Lonnberg, 'Albumins of the Kidney and Urinary Bladder,' Skandinav. Arch, 

 f. Physiol. 3. 1 (1890). 



4 L. Brauer, Zeitschr. f. physiol. Chem. 4O. 182 (1903). 



5 E. Salkowski, Virchoiv's Arch. 132. 304 (1893). 



