T. B. Osborne and A. J. Wakeman 8) 
and the solution filtered through a felt of paper pulp to remove 
traces of insoluble matter. The filtrate (about 1 liter) was 
again saturated with ammonium sulfate and the precipitate 
allowed to drain on filters over night. When dissolved in 
water, an opalescent, slightly acid, but transparent solution was 
obtained. A little of this when dropped into much distilled 
water gave a turbidity which disappeared on stirring, but no 
degree of dilution could be found at which a distinct separation 
of globulin took place. After saturating this solution with 
ammonium sulfate the precipitate was filtered out and pressed on 
filter paper over night under a heavy weight. By the foregoing 
' treatment the precipitate, which consisted of all of the milk 
proteins except those removed by acidifying the milk, was 
quite thoroughly freed from lactose and other non-protein con- 
stituents of the milk. The crumbly precipitate was then dis- 
solved in water, and, in order to remove globulin, its solution 
was saturated with magnesium sulfate. The resulting precipi- 
tate, A, was filtered out and treated as will be described on 
page 11. 
Lactalbumin. 
A sample of the filtrate from the globulin, which was per- 
fectly neutral to litmus, was diluted with three volumes of water 
and heated to 90°. <A flocculent coagulum separated very slowly. 
Another sample, when made distinctly acid to litmus with 
acetic acid, behaved in the same way. The remaining solution 
was diluted with three volumes of water, made slightly acid to 
litmus with acetic acid, and heated to boiling. The coagulum 
was filtered out, washed with -boiling water till freed from sul- 
fate, then with dilute, and finally with absolute alcohol, and 
dried over sulfuric acid. This preparation of coagulated lactal- 
bumin, which had been freed from globulin by saturating its 
neutral solution with magnesium sulfate, weighed 10.8 gm., 
contained 6.25 per cent of moisture, and 0.16 per cent of ash. 
Its composition, ash- and moisture-free, after drying at 110°, 
was: 
