352 
and Pages). Fuld (24) has recently suggested the name whey- 
albumose for the soluble proteid produced in the rennin coagulation 
of milk. This view also derives support from the more recent i 
researches on the subject by P. T. Muller (25), who found whey- i 
proteid in the milk serum only after rennin coagulation and not | 
after the milk had been coagulated by acids or lactoserum. Simi- 
larly, unpublished analyses by W. Laqueur (23) and an experiment I 
by Rotondi (26) also indicate the splitting off of a soluble nitroge- j 
nous compound from caseinogen during the rennin coagulation of 
milk. On the other hand, according to Duclaux (27), who analyzed 
the filtrates obtained by filtering fresh milk and milk coagulated by 
rennin through a porcelain filter, the soluble nitrogen in the whey 
is not increased after rennin coagulation, nor is the composition of 
the whey altered in any way. That such is the case may be seen 
from the following results of his analyses of milk serum before and 
- after coagulation by rennin: 
Experiment I. 
Experiment II. 
Normal 
milk. 
Milk coag- 
ulated by 
rennin. 
Normal 
milk. 
Milk coag- 
ulated by 
rennin. 
Lactose 
5.53 
5.53 
5.37 
5.64 
Soluble albumin 
.55 
.57 
.37 
.36 
Mineral matter 
.54 
.52 
.56 
.40 
Arrhenius (28) is of the opinion, however, that Duclaux's experi- 
ments on this point are not convincing, since the whey proteid might j 
have been retained b}^ the porcelain filter, especially in the presence \ 
of the gelatinous paracasein. ^ 
From his researches on the laws governing rennin coagulation Fuld 
(29) also arrived at the conclusion that the transformation of case- 
inogen into jDaracasein is onh^ a molecular rearrangement, partaking 
of the nature of a monomolecular process. According to this author 
the rennin coagulation of milk is only a special case of the well-known 
phenomenon of the reciprocal suspension and precipitation of col- 
loidal substances. Loevenhart (14) has also reached the conclusion 
that it is probable that caseinogen and paracasein are chemically the 
same substance, and that the observed differences existing between 
them depend upon the fact that paracasein exhibits a higher degree of 
association than caseinogen. In other words, paracasein consists of 
larger molecular aggregates than caseinogen, otherwise they are 
identical. These views are shared by other observers, among them 
Van Slyke and Hart (30). On the other hand, Laqueur (23), from a 
consideration of these facts and the conduct of other colloidal sub- 
