270 Report oF THE CHEMIST OF THR 
Basic calcium paracasein, containing free paracasein combined 
with about 2.40 per ct. of CaO. 
Neutral calcium paracasein, calcium paracasein containing 
about 1.50 per ct. of CaO in combination, probably identical with 
the uncoagulated body present in cows’ milk treated with rennet 
enzym in the absence of soluble calcium salts. 
Paracasein salts of acids, compounds existing as precipitates 
and formed by combination of the free paracasein with acid. 
In most of the literature on the subject, the word casein is 
used indiscriminately to mean milk-casein, free casein, or those 
casein salts formed by acid precipitation. In many cases it is 
used comprehensively to include all the .proteids in cows’ milk. 
A. similar state of confusion exists in regard to the use of the 
word paracasein. it would therefore seem pertinent to make the 
following suggestions, tentatively at least, in regard to the 
nomenclature of these compounds: 
(1) That the word casein be applied only to the free proteid, 
that is, the base-free casein. 
(2) That the compound existing in cows’ milk and commonly 
called casein be called calcium casein. 
(3) That the casein compound containing about 2.40 per ct. of 
CaO be called basic calcium casein. 
(4) That a compound formed by precipitation and combina- 
tion with an acid be called a casein salt of the acid used. 
(5) That the same nomenclature be applied to the correspond- 
ing paracasein bodies, simply substituting the word paracasein 
for casein, with the following addition: Calcium paracasein 
should be applied to the uncoagulated substance produced in 
milk by rennet enzym, while the coagulum of this substance 
caused by soluble calcium salts should be called coagulated cal- 
cium paracasein. 
THE RELATION OF THE RESULTS TO CERTAIN CHANGES 
TAKING PLACE DURING THE CHEESE-MAKING 
PROCESS. 
In the manufacture of cheddar and similar types of cheese, 
after the addition of rennet enzym, and coagulation, there takes 
place a progressive change, resulting in the production of in- 
creased amounts of a proteid soluble in warm 5 per ct. solution 
