New YorK AGRICULTURAL EXPERIMENT STATION. 167 
(5th.) Mixture containing (a) proteid soluble in salt solution, 
(b) proteid insoluble in salt solution and (c) water-soluble pro- 
teids, the second form (insoluble in salt solution) decreasing 
and the water-soluble form increasing. In all of the analyses 
of cheese previously published! it is noticeable that there is 
always present in varying proportions each of these three differ- 
ent forms of proteid. 
In order to show more clearly how this recent view of the 
series of changes in cheddar cheese differs from the former con- 
ception, we give the following statement of the views previously 
held: The succession of changes was believed to consist of 
(1) change from insoluble proteid (calcium paracasein) into (2) 
proteid soluble in salt solution, and this into (3) water-soluble 
proteids, under which conditions we were supposed to have — 
(1st.) All insoluble proteid (calcium paracasein). 
(2d.) Mixture of (a) insoluble proteid and (b) proteid soluble 
in salt solution. 
(3d.) Mixture of (a) insoluble proteid, (b) proteid soluble in 
salt solution, and (c) water-soluble proteids. 
It is thus seen that, according to the view formerly held, two 
points in the series of changes were entirely overlooked: (1) the 
complete conversion of the insoluble proteid (calcium paracasein) 
into salt-soluble proteid, and (2) the conversion of salt-soluble 
proteid into insoluble proteid. We formerly believed that the 
calcium paracasein of the fresh cheese-curd was at no time 
completely changed into salt-soluble or water-soluble forms, but 
that it persisted in some amount throughout the cheese-ripening 
process; whereas the insoluble proteid commonly found in ched- 
dar cheese, now appears to be the product formed directly from 
the salt-soluble proteid. 
The newer view is more complex in that it involves more 
changes, but is somewhat simpler in that the first step in the 
series of changes appears to be complete before the succeeding 
one takes place, that is, all the calcium paracasein appears to be 
changed into salt-soluble proteid before the succeeding insoluble 
proteid is formed. 
The newer view also makes clear a point which was never 
satisfactorily explained under the former conception. While 
it was held that water-soluble proteid in cheese was formed 
directly from the salt-soluble proteid, the fornter increasing while 
*Buls. 214, 233, 234, 236 of this Station. 
