DIFFUSIBLE PHOSPHORUS OF COW'S MILK. 259 
four hours. At the end ofthis time the molecular concen- 
trations ofsthe dissolved substances on each side of the 
celloidin membrane were practically the same. The relative 
molecular concentrations of milk and its dialysates were 
determined by measuring the depressions of the freezing 
point of water (A) due to the substances in solution in 
these liquids. The following are the figures obtained. 
Values of A for spun milk, twenty-four hour dialysate, and forty-eight 
hour dralysate. 
Experiment. Spun milk. 24-hr. Dialysate. | 48-hr. Dialysate. 
i ely Os56dS 5 0:580° 0-576° 
62 0:576 0-547 0:533 
63 0-569 0°530 0°526 
64 0:560 0:535 0°539 
These results show that the values of / for milk from 
which the fat has been removed by spinning in a centrifuge 
{spun milk) and for the twenty-four hour and forty-eight 
hour dialysates agree to within about 57%, and that the 
freezing point of the dialysate does not alter its value once 
it has approximated to that of milk. When it is remem- 
bered that the diffusible part of the milk has been diluted 
to the extent of 2°57 it will be seen that a closer agree- 
ment between the freezing points of milk and its dialysates 
is hardly to be expected. An experiment in which the 
values of /\ for spun milk, dialysate and the milk in equi- 
librium with the dialysate were determined, gave the 
following results. 
0°560° | ~——-0°5 42° 0°548° 
The values of /\ for the dialysate and the liquid in equi- 
librium with it thus agree very closely. 
Spun Milk. | Dialysate. Outer Liquid. 
It will be noticed that the freezing points of the dialy- 
sates have been compared, not with the milk with which 
