The New Student's Reference Work/Butter

Butter, the fatty part of milk, obtained from milk or cream by churning.  Milk is made up of three parts, the cheesy portion or curd, the whey or watery part which contains milk-sugar, and the butter; and when examined by the microscope is seen to consist of a number of little globules of fat floating in a clear liquid.  These globules collect and form cream after the milk has stood a few hours, and the process of butter making or churning is simply to cause the particles of fat to come together in a mass.  After churning, the butter is washed and salt added to prevent the forming of certain acids which give old butter its rancid taste.  Besides the common method of churning, butter is made in parts of South America, by jolting the cream, which is put in gourds or skin bags, on the backs of donkeys, or, as in Buenos Ayres, by dragging it in a skin-bag behind a galloping horseman.  Indeed, butter is said to have been discovered by carrying milk in skin bottles on camels, in which the butter was made by the jolting.  It takes about two quarts of cream to make one pound of butter.  Artificial butter, called oleomargarine, is now made from beef-fat.