BULLETIN 
U. S. DEPARTMENT OF AGRICULTURE. 
in ice until the next morning when observations were begun. The 
chemical analyses of the samples were as follows: 3 J per cent milk: 
12.68 per cent total solids, 9.18 per cent solids not fat, 87.32 per cent 
water; 20 per cent cream: 27.27 per cent total solids, 7.27 per cent 
solids not fat, 72.73 per cent water; 40 per cent cream: 44.30 per cent 
total solids, 4.30 per cent solids not fat, 55.70 psr cent water. 
In view of the fact that only a single test on one sample of the 
material was made the results can be considered only as tentative 
and not final. 
Table I. — Specific heat of milk and cream. 
Temperature. 
Milk. 
20 
per cent 
cream. 
40 
per cent 
cream. 
Temperature. 
Milk. 
20 
per cent 
cream. 
40 
per cent 
cream. 
°F. 
35.6 
°C. 
2.0 
3.0 
6.5 
9.0 
11.0 
13.0 
15.0 
19.0 
22.0 
24.0 
26.0 
28.0 
30.0 
32.0 
0.88 
°F. 
95.9 
100.4 
105.8 
109.4 
114.8 
118.4 
123.8 
127.4 
131.0 
136.4 
141.8 
145.4 
150.8 
°C. 
35.5 
38.0 
41.0 
43.0 
46.0 
48.0 
51.0 
53.0 
55.0 
58.0 
61.0 
63.0 
66.0 
0.93 
0.89 
86 
37.4 
0.92 
.92 
0.83 
.90 
.80 
43.7 
.91 
.92 
.92 
.87 
48.2 
78 
51.8 
.93 
.96 
.87 
55.4 
.94 
.95 
1.01 
.95 
.92 
.78 
59.0 
.94 
.95 
.94 
1.02 
1.07 
.86 
66.2 
.77 
71.6 
.93 
.86 
75.2 
.93 
.88 
.76 
78.8 
.93 
.93 
.87 
82.4 
.91 
.72 
86.0 
.92 
.88 
.94 
89.6 
.91 

The curves, figure 1, show the specific heat of 3^ per cent milk and 
20 and 40 per cent cream at different temperatures between 35.6° F. 
and 150.8° F. 
COHESION AND VISCOSITY OF MILK. 
Milk upon cooling assumes a denser semiliquid aspect and sticks 
more closely to the walls of the vessel than when warm. Conse- 
quently it is harder to clean, by means of water, a vessel that has 
contained cold milk than one that has contained warm milk. On the 
other hand, for the same reason, it is more difficult to cleanse vessels 
that have contained milk by the use of cold water than by the use of 
warm water. Milk is more liable to foam when cold than when hot, 
and the foam will keep longer. The foam, however, will disappear if 
the milk is heated. With the lowering of the temperature of milk the 
cohesion increases in proportion to its viscosity. 
At 86° F. the viscosity is about 1.7 times as great in milk as it is 
in water, while at 32° F. its viscosity is about 2.4 times that of water. 
At 32° F. the viscosity of milk is about 2.6 times as great as it is at 
86° F. 
