DIFFUSIBLE PHOSPHORUS OF COW’S MILK. DoS 
On THE DIFFUSIBLH PHOSPHORUS or COW’S MILK. 
By H. S. HALCRO WARDLAW, B.Sc., 
Science Research Scholar of the University of Sydney. 
(From the Physiological Laboratory of the University of Sydney.) 
[Read before the Royal Society of N. S. Wales, August 5, 1914. | 
NUMEROUS data are available concerning the total quanti- 
ties of the various elements which are present in milk. 
With regard to the forms of chemical combination and to: 
the physical states in which these elements exist, however, 
our knowledge is much less complete. We know that milk 
contains substances both in solution and in suspension, but. 
as to how the different elements are distributed between 
these states very few reliable data are to be found. 
The separation of the substances in suspension in milk 
from those in solution has been attempted in three chief 
ways :— 
1. By forcing milk through a filter made of some material 
having extremely fine pores, such as unglazed 
porcelain. A perfectly clear filtrate is obtained by 
this process. 
2. By spinning milkinacentrifuge. In this way portion 
of the suspended matter of milk is obtained as a 
deposit. 
3. By allowing the soluble portion of milk to dialyse 
away from the substances in suspension. 
Although the first method of separation has been known 
for many years, few statements as to proportions of the 
substances in milk which pass through a porcelain filter are 
to be found, and there are considerable discrepancies. 
