T. B. Osborne and A. J. Wakeman 15 
within an hour after drawing from the cow, gave a precipitate 
which, when worked up as rapidly as possible, yielded substan- 
tially the same result as did milk 12 hours old when similarly 
treated. The acidity of the filtrate from casein, precipitated 
by either hydrochloric, or by acetic acid, in the presence, or 
absence, of phosphates, or of sulfates is pH = 4.64 so that co- 
agulation in most. of our experiments took place at practically 
the same degree of acidity. At this degree of acidity some 
alteration of the globulin or albumin may take place during the 
heating. necessary to coagulate these proteins. We have founa 
however, that if fresh milk is heated to boiling before acidifying 
and casein together with the coagulated proteins is subsequently 
removed by acidifying and filtering, a small amount of uncoagu- 
lated protein still remains in solution. 
No method that we have as yet devised has enabled us to obtain 
evidence that a certain but relatively very small amount of pro- 
teose may not be an original constituent of cow’s milk. In our 
last attempt we obtained per liter of milk only 0.2 gm. of pro- 
tein resembling proteose although mechanical losses were at the 
most very small. Until the conditions under which coagulation 
of the globulin and albumin can be quantitatively effected are 
established we shall not be in a position to determine definitely 
whether or not milk contains any proteose. 
Stegfried’s “Nucleon.” 
Siegfried® obtained from the extract of horse muscle a substance 
which he called Flezschsdure. This he believed to occur in com- 
bination with phosphoric acid, which compound he first named 
Phosphorfleischsdure. Since Fleischsdéure appeared to be identical 
with antipeptone,® Siegfried later proposed to call the phosphoric 
acid combination nucleon’? on account of the similarity of its 
products of hydrolysis to those of the nucleins. Nucleon can be 
precipitated as an iron compound, carniferrin, which contains 
4Cf. Allemann, O., Biochem. Z., 1912, xlv, 346. Michaelis, L., and 
Pechstein, H., ibid., 1912, xlvii, 260. 
6 Siegfried, M., Ber. Sdchs. Ges. Wissensch. zu Levpzvg, Math. u. phys: 
Classe, 1893, xlv, 485. 
6 Siegfried, Arch. Phystiol., 1894, 401. 
7 Siegfried, Ber. chem. Ges., 1895, xxviil, 515. 
