10 Proteins of Cow’s Milk 
Lactalbumin Free from Globulin. 
Coagulated. 
Sebelien.? 
I II Average. 
CArDON (2c 8- see cede ea ee tos ee ee 52.61 52.42 52.51 52.91 
Hydrogen (vers nk nee 7.18 7.01 7.10 7.18 
Nitrogen. {9 cia dian: a eee 15.38 15.48 15.48 15.77 
DUITUT' sprain cela. none ene 1.92 1.92 1.73 
Phosphorus... eke ow cee Trace. Trace. 0.18 
Oxyren (by difference) cre yn ee (sn oe ee 23 .04 
In harmony with the fact that this coagulated preparation 
of lactalbumin contained only a trace of phosphorus we found that 
another preparation which had been similarly precipitated by 
saturation with magnesium sulfate, but had not been coagulated 
by heat, when extracted with alcohol yielded only an insignifi- 
cant amount of substance resembling phosphatide, and that this 
contained only a trace of phosphorus. It is thus evident that 
the phosphatide, which we previously obtained from the coagu- 
lated protein of milk,’ is not associated with the purified lact- 
albumin. 
The filtrate from our coagulated lactalbumin gave a slight 
flocculent precipitate with acetic acid and potassium ferrocyanide, 
showing the presence of a very little still uncoagulated protein. 
That a very complete separation of globulin from albumin is 
obtained by the method employed in making this preparation is 
shown by the results of anaphylaxis experiments made by H. G. 
Wells with another preparation made in the same way, except that 
the final precipitation of the albumin was effected by acidifying 
the filtrate from the globulin precipitated with magnesium sul- 
fate, instead of by heating. This precipitate was freed from most 
of the adhering solution of magnesium sulfate by pressing between 
layers of filter paper, and was then dried over sulfuric acid. 
The preparation thus obtained, which still contained much 
magnesium sulfate, was perfectly soluble in water. | Guinea 
pigs sensitized by this preparation were promptly killed by a 
? Sebelien, J., Z. physiol. Chem., 1885, ix, 463. ? 
3 Osborne, T. B., and Wakeman, A. J., J. Biol. Chem., 1915, xxi, 539. 
