Gravity Processes of Creaming 167 
increase the amount of solids not fat, we shenld ex- 
-- pect such milk to be more easily creamed, but the 
favorable effect of the increase of solids is more 
than counterbalanced by the unfavorable effect of 
the character of the solids. Of the solids not fat, 
albumin, casein, sugar and ash increase the viscos- 
‘ity of the milk in the order named, and of these 
the casein is more subject to variation, so that the 
increase in the proportion of solids not fat ordi- 
narily means an increase in casein, and this means 
a largely increased viscosity. And the increase in 
viscosity tends to prevent the separation of the fat 
more than the increase in specific gravity tends to 
aid it. In general, the conditions which bring about 
an increase in the viscosity of the milk occur at the 
same time as the fat globules are growing smaller, so 
that we find a wide range of variability in the ease 
and completeness with which cream may be separated 
by gravity process. 
Shallow pan creaming.—This' is the oldest method 
of separating cream from milk, and notwithstanding 
the rapid changes that have taken place in cream- 
ing methods since the introduction of centrifugal 
separators, large amounts of butter are still made 
from cream separated in this way. The conditions 
most favorable for a complete separation of the fat 
in the shallow pan: system are, that the milk should 
be put at rest in the pans as quickly as possible 
after it is drawn, that it should cool with a fair de- 
gree of rapidity to a temperature of 60° F., and that 
it should remain as nearly as may be constantly at 
