468 REPORT OF THE CHEMIST OF THE 
We will state here the characteristics of the three different 
nitrogen compounds of milk. Casein is that portion of the milk ) 
whicli is coagulated by rennet and acids, but not by heat alone. 
Albumen is that portion of milk coagulated by heat, but not by 
acids or rennet. Albumose is that portion of milk coagulated 
by neither heat, rennet nor acids; it, therefore, remains in solu- 
tion under those conditions which cause the coagulation of casein 
and albumen. There has been for some time a question as to 
the possibility of holding all the nitrogen compounds of milk in 
cheese by some practical method. It has been supposed that the 
albumen formed most of the nitrogen compounds remaining 
after the removal of casein; but, as will be seen, our figures 
show that the larger portion of what we have called albumen is 
albumose, ard that heat has no effect in coagulating it. Hence, 
if there were a practicable method of retaining albumen in 
cheese, we should be able to retain only one-third of a pound for 
100 pounds of milk, instead of three-fourths of a pound, as has 
previously been expected. 
TaBLE £HOWING PRopoRTION OF CasEIN IN THE NiTROGEN Com- : 
PouNDS OF MILK. | 







A 5 
May. | June. . July. | August, pie October. "fore ‘ 
. 4 | €eason, > 
fe Bel oe i 
Least .....1.75.48 | 74.92 | 73.49 | 75.25 | 74.267) 76.01 |) i 
Greatest...) 79.00°) 78.40 |'77:21 4 77.30 |, 81.29°|.79 044) Ree 
Average ..| 77.71 | 76.55 | 75.661) 76.07 |. 74774 | 77.8891 | 7700" am 
| E 
= AR Ae NON POD ON A a ASME Lath Ps We : 



a. The proportion of nitrogen compounds in milk that con- 
sisted of casein varied from 73.49 to 81.29 per cent., and aver- 
aged 77 per cent. 
b. The proportion of casein in the nitrogen compounds of ag 
milk decreased in June and July, and then increased during the _ 
remainder of the season. 5 
