The heat value of a gram of pure, water-free protein--for example, the casein of milk, egg albumen, or fiber of meat--is a trifle more than four calories. That of pure starch or sugar is also four calories. Fat is more than double this value, one gram yielding nine and three tenths calories. Since an ounce equals about thirty grams, the number of calories to an ounce is determined by multiplying the above figures by thirty. Different kinds of food vary greatly in the proportion of the food elements and also of the water and cellulose they contain. (Cellulose has no fuel value in the human body.) We therefore find a great variation as to their caloric values also. For example, one heaping tablespoonful of home-baked beans will weigh about fifty grams, thirty of which is water and cellulose. Its total caloric value is one hundred, divided among protein fifteen, fat forty (the fat has largely been added), and carbohydrate forty-five. Contrast with this the same quantity of mashed turnips. One heaping tablespoonful will weigh about seventy grams, of which sixty-five is water and cellulose. Its total fuel value is three calories. By a little study, one may very readily become familiar with the approximate values of the more common foods, and be able to arrive at some conclusion in regard to the correctness of one's daily food ration as to amount and proportions. Many would be surprised to see how far short their diet comes of the ideal. It is easy to remember that an ordinary slice of bread--about three and one half inches square--contains approximately one hundred calories; an average egg, sixty-five; a glass of milk, one hundred fifty; an average potato, one hundred twenty-five; a tablespoonful of gravity cream, fifty; the usual serving of cooked cereal, seventy-five to one hundred; vegetables, except potatoes, an ordinary serving, twenty-five to fifty, depending on the amount of fat or milk added as seasoning; legumes, average serving, one hundred to one hundred fifty. Desserts are usually high in value, ranging from one hundred twenty-five calories in the usual serving of simple custard or junket to three hundred fifty or more in the usual one sixth of some pies, or the ordinary piece of cake. Housewives who wish to go into the question of foods thoroughly, and combine the science with the art of cookery, may arrange a table of the staples and raw food that ordinarily enter into their various recipes, somewhat after the following, the items of which have been taken at random from such a list or table already prepared and in use: A. _Food_ B. _Measure_ C. _Weight_ D. _Protein_ E. _Fat_ F. _Carbohydrate_ G. _Total_ A B C D E F G