264 
H. S. H. WARDLAW. 
ponding figures are required. The correction is not large, 
and for comparative purposes need not be made. 
Amount of diffusible CaO.—The estimations of CaO were 
made by the method of Aron (1907) in which the Ca is pre- 
cipitated from the acid ash as CaSO, by the addition of 
alcohol. The figures below give the proportions of diffusible 
CaO found in three samples of milk. 
Percentage of CaO of milk in a diffusible condition. 
CaO in 100 ce. of Percentage in 
Milk. Spun milk. Dialysate. dialysate. 
A B 24-hour. | 48-hour. | 24-hour. | 48-hour.  _ 
55 0°180 0-166 | 0-061 o0"o 
56 0:164 0-153.) 0:061 ae 30'S Me 
58 0-280 0-086 0:077 30°8 27°4 
The agreement between the duplicate analyses is not 
good, but the results show that roundly 30—407 of the 
calcium of milk is present in a diffusible state. These 
figures are rather lower than those given by Rona and 
Michaelis for the four samples of milk examined by them. 
Their figures range from 40 to 50%; they give no duplicate 
analyses. 
Amount of diffusible P.O0;.—The phosphates in the acid 
ash were precipitated in the way described by Neumann. 
These precipitates were dissolved in dilute ammonium 
hydroxide, the P.O, was precipitated again as MgNH,POQ,, 
and finally weighed as Mg.P.O, in the usual manner. The 
details of these processes will be found in the author’s 
previous papers (loc. cit.1 and 2). The accompanying 
figures show the results obtained for the amounts of 
diffusible P,O;. 
