Milk, alone of all foods, enters the stomach a liquid and becomes there a more solid food. This hidden and insidious solidness, if I may use the term, is peculiarly characteristic of raw cow's milk, as compared with boiled cow's milk, or human milk. The housewife and the dairyman are practically familiar with the fact that boiled milk forms a different curd from raw milk. We, on the other hand, have quite ignored the fact that raw and boiled milk are not identical foods. If we have thought of it at all it has been rather from a bacteriologic than from a physiologic point of view. And yet boiled cow's milk forms in the stomach, as does human milk, nearly a liquid food; while raw cow's milk, as I shall hope to demonstrate, is not even a soft food, but a solid food, so solid, in fact, that, unless modified