But its composition, as already intimated, varies exceedingly with the food of the animal, and is influenced by an infinite variety of circumstances.
Skim-milk is much more watery than whole milk. It was found by one analysis to contain about 97 per cent. of water and 3 per cent. of caseine.
Swill-milk, or milk from cows fed on “still-slops,” in New York, was found by analysis to contain less than 1.5 per cent. of butter, some specimens having even less than one per cent.
The colostrum, or milk of the cow just after calving, contains a large proportion of cheesy matter. Its amount of caseine was found by careful analysis to be 15.1 per cent., of butter 2.6, mucous matter 2, and water 80.3, there being only a trace of sugar of milk.
The measures for milk in common use in this country are those used for wine and beer. The wine quart is about one fifth less than the beer quart, and is that most commonly used in England. It is to be regretted that no uniform standard has been adopted throughout the country.
CHAPTER VIII.
BUTTER AND THE BUTTER-DAIRY.
“Slow rolls the churn—its load of clogging cream
At once foregoes its quality and name.
From knotty particles first floating wide,
Congealing butter’s dashed from side to side.”
Butter, as we have seen, is the oily or fatty constituent of all good milk, mechanically united or held in suspension by the solution of caseine or cheesy matter in water. It is already formed in the udder of the cow, and the operations required after it leaves the udder, to produce it, effect merely the separation, more or less complete, of the butter from the cheese and the whey.
This being the case, it is natural to suppose that butter was known at an early date. The wandering tribes, accustomed to take on their journeys a supply of milk in skins, would find it formed by the agitation of travelling, and thus would be suggested the first rude and simple process of churning.