Deerfoot Farm Centrifugal Dairy. 
479 
including the outer layer where the scum accumulates, show a 
composition as nearly identical as can be expected, and no 
increase of casein, a fact which, while not opposed to this view, 
yet cannot be considered confirmatory. 
The morphological relations of milk are those which concern 
us the most in our studies into the effect of centrifugal force 
upon this product of the cow, and hence the necessity of these 
preliminary observations bearing upon this form-character. In 
this aspect the chemical relations are of less importance. \^e, 
however, would summarise briefly a few facts that are conclu- 
sively established, and a few other circumstances which are as 
probably true. 
There is no relation between the percentage of cream and 
percentage of butter that can be made therefrom. Hence, it is 
an absolute fact that the cream per cent, does not indicate the 
butter quantitative quality of the milk. The appearance of the 
cream does, however, afford us strong ground for a presumption 
that the denser the cream the more the butter that it will make. 
A cream percentage of 20 per cent., if by a constant series of 
jarrings it be reduced to 10 or 12 per cent., will make the same 
quantity of butter in its new form as in its old form. 
The fat shown by analysis to exist in milk does not all appear 
as butter when the milk is churned. Churning is a physical 
process and acts upon the larger globules only. Hence, of two 
milks, showing like figures to analysis, the churn will separate 
more butter from one than the other, especially if the milks be 
from two distinct breeds of cows. 
There exists in milk, under normal circumstances, a propor- 
tion of albumen varying from one-third to three-quarters per 
cent. There also exists an undetermined proportion of what 
may be called mucus, the wear and tear of the cow under the 
action of milk formation. 
The casein of milk from different races has distinct properties. 
In human milk, when coagulated and dried, it possesses a 
friable character. In the milk of the bitch it does not become 
viscid and horny on drying. In cow's milk it becomes viscid 
and horny on drying. It also varies in character in the milks 
from different breeds of cows, being more horny on drying in 
the milk of the Jersey than in that of the Ayrshire breed. 
Rennet precipitates the coagulum with greater or less ease in 
different milks, as do also mineral acids. 
The importance of alluding to these considerations will 
appear when we come to describe and discuss the practical rela- 
tions of centrifugal force to the dairy. 
Deerfoot Herd. — The foundation of the milk industry is the 
cow, and hence we must commence by describing Mr. Burnett's 
