TOO REPORT OF THE CHEMIST OF THE 
by extraction with water. This was shown by determining the 
amount of lactate in cheese by the method given on p. 155, and 
also in the water-extract prepared as described above. For 
illustration, in the cheese itself we found in one case 0.58 per ct. 
of calcium lactate and in the water-extract, 0.587 per ct. 
DISCUSSION OF RESULTS. 
We will now bring together in comprehensive form the results 
of the experiments described in this bulletin and discuss them 
with the purpose of seeking an interpretation of them in their 
application to cheddar cheese. We will consider the results 
under the following headings: (1) Changes in the proteids of . 
cheddar cheese, (2) the changes in calcium and phosphoric acid 
compounds. 
CHANGES IN THE PROTEIDS OF CHEDDAR CHEESE. 
In the manufacture of cheddar cheese, the proteid of the in- 
soluble curd (calcium paracasein) changes rapidly into a form 
that is soluble in 5 per ct. solution of sodium chloride at 50 to 
55° C., until, in a few hours (9 or 10) after putting in press, the 
proteid, originally insoluble in warm dilute salt solution, be- 
comes completely soluble in this solution. After reaching this 
condition of solubility, the brine-soluble proteid undergoes an- 
other change into a form that is insoluble in warm dilute salt 
solution, the change going on rapidly at first and then gradually. 
Proteid in water-soluble form appears to increase only slightly, 
if any, until after all the proteid has become soluble in warm, 
dilute salt solution and has then changed to some extent into 
a form insoluble in salt solution. , 
Thus, there appears to be the following series of successive 
changes: (1) From insoluble proteid as represented in the fresh 
curd (calcium paracasein) into (2) proteid soluble in warm, 
dilute salt solution, this into (3) proteid insoluble in salt solu- 
tion and this into (4) water-soluble proteid. Under these con- 
ditions, we should have: 
(1st.) All insoluble proteid (calcium paracasein). 
(2d.) Mixture of (a) insoluble proteid and (b) proteid soluble 
in salt solution, the latter increasing at the expense of the former. 
(3d.) All salt-soluble proteid. 
(4th.) Mixture containing (a) salt-soluble proteid and (b) 
proteid insoluble in salt solution, the former predominating at 
first and then diminishing while the latter increases. 
