Note H — Chapter IV
Reading edition
The organic materials of human diet are usually classified into three divisions:—
(1) The Proteids, or Albuminates—the characterising element occurring being nitrogen. The nitrogenous foods are: flesh (without the fat), eggs, milk, cheese, legumes (peas, beans, lentils, etc.).
(2) The Fats, or Hydro-carbons. All animal and vegetable fats and oil. Emulsions of mineral oils have been shown to pass through the system unchanged, and therefore cannot be regarded as food.
(3) The Carbohydrates (sugars and starches): bread, potatoes, and grain generally.
Protein is the tissue builder; heat and energy are derived largely from the non-nitrogenous foods.
A Calorie (large) is the unit of heat required to raise one kilogram of water to 1° C. The full value of a food is ascertained by means of the calorimeter, or apparatus used to determine the specific heat of substances, or the amounts of heat evolved or absorbed in various physical and chemical changes. Calorimeters take very diverse forms, varying from quite simple vessels to highly complex apparatus, according to the particular kind of determination to be carried out in them.