New York AGRICULTURAL EXPERIMENT STATION. 219 
AVERAGE PROFITS DERIVED FROM SELLING MILK AND ITS PRODUCTS FOR ONE 
3 PERIOD OF LACTATION. 
(a) From cheese, $9.79. 
(b) From milk, $19.80. 
(c) From butter, $25.64. 
(d) From cream, $72.52. 
THE AMOUNT OF PROFIT GAINED IN SELLING MILK AND ITS PRODUCTS IN ONE 
FORM OVER OTHER FORMS. 
(a) Butter over milk, $5.84 profit. 
(b) Milk over cheese, $10.00 profit. 
(c) Butter over cheese, $15.85 profit. 
(d) Cream over butter, $46.88 profit. 
(e) Cream over miik, $52.72 profit. 
(f) Cream over cheese, $62.73 profit. 
COMPARATIVE STATEMENT OF PROFITS DERIVED FROM SELLING MILK AND ITS 
PRODUCTS. 
(a) Ratio of profit of milk to butter, I: 1.30. 
(b) Ratio of profit of cheese to milk, 1: 2.02. 
(c) Ratio of profit of cheese to butter, I: 2.62. 
(d) Ratio of profit of butter to cream, 1: 2.83. 
(e) Ratio of profit of milk to cream, 1: 3.66. 
(f) Ratio of profit of cheese to cream, I: 7.40. 
ie PROTEIDS: Ob. BUIIER. IN. RELATION .TO 
MOTTLED BUTTERS 
Little study has been made of the proteids of cream, buttermilk 
and butter, especially in relation to mottled butter. The form of 
casein in cream ripened by ordinary methods of creaming is free 
casein when the lactic acid is allowed to exceed 0.5 per ct. Free 
casein, the result of combination of lactic acid with the calcium 
of the calcium casein of normal sweet milk, holding more or less 
lactic acid is the substance most familiar as curdled sour milk. 
When the amount of lactic acid in cream exceeds 0.5 per ct., the 
casein in the butter and buttermilk is present as free casein holding 
more or less lactic acid by adsorption. In butter and buttermilk 
made from so-called sweet cream, we usually find calcium casein 
and some free casein, but, on standing some weeks, these may be 
changed in the butter into free casein. 
It has been quite universally believed that the light-colored spots 
or streaks in butter, known as mottles, are caused solely by the 
uneven distribution of salt without reference to the composition of 
** Bul. 263. 
