DIFFUSIBLE PHOSPHORUS OF COW’S MILK. eel 
Michaelis have determined the amount of diffusible calcium 
in milk. 
This paper is an account of the application of the method 
of quantitative dialysis to the study of the diffusible phos- 
phorus of cow’s milk. A few determinations of the diffusible 
calcium have also been made. 
The Milk Used. 
The milk used for the first experiment was ordinary mixed 
milk as supplied by a city milk-vendor. This milk is about 
twelve hours old before it reaches the consumer, and is 
generally pasteurised. Such milk was found quite unsuit- 
able for the present work as even the addition of toluol did 
not prevent its souring before the completion of the dialysis. 
The remaining experiments were made upon the milks of 
single cows. Hach cow from which a sample of milk was 
taken, was milked directly into a vessel containing 10 cc. 
of toluol for each litre of milk collected. The access of 
bacteria is very much hindered in this way; milk collected 
as described keeps sweet for several days. The essential 
point here seems to be to prevent the entrance of bacteria, 
as it has been shown that although toluol kills organisms, 
such as yeasts, it has practically no efiect on the rate of 
action of the enzymes produced by them (Harden, 1910). 
Toluol was chosen as the disinfectant as being a hydro- 
carbon and practically insoluble in water it did not seem 
likely to have any marked effect on the substances in an 
aqueous solution suchas milk. Toluol does exert a solvent 
action on the fat of milk, however. 
The samples of milk were all collected at about 12 noon; 
the last milking of the same cow had occurred in each case 
at about 4a.m. of the same day. The milk obtained was 
generally the first portion of the milking. 
The Dialyses. 
The dialysis of milk against water was allowed to take 
place through celloidin membranes. These membranes 
Q—July 1, 1914. 
