Notes from Janice’s Desk
When I was a kid milk was pasteurized. At the time I didn’t understand that pasteurized meant the milk was heated to kill any bacteria. In fact I never thought about the word until a new kind of milk was introduce. This new stuff was call homogenized and my parents were not happy with it. Mom called the homogenized “Blue John” milk, which is milk after most of the cream has been removed to make butter. She thought this because the cream in the pasteurized milk rose to the surface and form a thick layer. Mom was not correct in her thinking that homogenized milk had the cream removed. Instead, the homogenized milk had the same amount of cream, but the cream particles were so tiny that they could not be seen and were evenly spread throughout the milk.
These two kinds of milk are perfect examples of two kinds of mixtures, pasteurized being a heterogeneous mixture and homogeneous mixture. Heterogeneous mixtures are not the same throughout, while homogeneous mixtures are the same throughout.