The early idea was that the heat of the body comes from the burning of the food and that the combustion takes place in the lungs. Then a later theory obtained to the effect that

the combustion takes place, not particularly in the lungs, but in all the tissues of the body, and most especially in the muscles. Following that came the theory that not alone the heat of the body, but all the work is done by the combustion of the food. Another equally short, and the last step, brings us to the strictly modern view that the food consumed in the body yields, in general, the same amount of heat and work as if it had been dried and burned under the boiler of a steam engine or exploded in the cylinder of a motorcar; with this difference, however, the steam engine has no power of renewing, strengthening, or developing itself, whereas the human body has that power.

The conclusion of the whole matter, then, is this: The true test of food value is its fuel value.

DAILY FOOD REQUIREMENTS IN CALORIES

Below is given a table, by Rubner, showing the number of heat units, or calories, necessary for the daily food supply for persons of different body weights.

DAILY FOOD REQUIREMENTS FOR PERSONS AT LIGHT WORK RUBNER STANDARD

For farmers or mechanics, at moderately hard work, add five hundred calories. For very heavy work add one thousand calories.

The table on pages 94 and 95 will be of value to all who desire to regulate their diet on a basis of fuel value, and that is the only true or accurate way to use food.

It is as important to know the relative food values of different foods as the value of inches, or ounces, or dimes.

SOME SCATTERING SUGGESTIONS AND POINTED PARAGRAPHS

1. Enough is better than a feast.

2. Milk is the universal food and the cheapest.

3. The danger of a strictly vegetable diet is the shortage of fats.

4. Don't fatten your garbage can with good food. 5. Starvation rations are not economy.

plenty, but wisely and well.

We must eat

6. Do you know that stale bread has more "heat units" than fresh bread, if not so palatable?

7. Oleomargarine is a clean, wholesome product and a good substitute for butter.

8. A child's food should be easier to digest than an adult's, and it should be more nutritious.

9. Proteins, on a bountiful table, will generally add up two or three times as much as is needed.

10. Milk is about eighty-five per cent. water and with that it is the cheapest and best food you can buy for the money it costs.

II. Cold storage eggs are wholesome-if they were wholesome when they went into storage.

12. Have at least one wheatless meal a day, and several meatless meals a week.

13. The starches and sugars in our food differ only slightly from each other. Starch is changed to sugar easily

and quickly.

14.. If you cut the bread on the table as it is eaten and do not slice up a plate full in the kitchen, you can easily save a pound of bread per week in your family. If every family would do this we will be able to send abroad not less than twenty million bushels more of wheat per year.

The most desirable fats are the uncooked fats with a low melting point, like olive oil, cream, butter, the yolk of eggs, nuts and cod-liver oil.

The most nutritious of the foodstuffs are hardest to digest, and the most difficult to manage wisely in the daily food supply.

All the water we drink in a year does not add a single calorie to our diet, yet we die more promptly for lack of water than from lack of all nutritious foodstuffs combined. So of mineral salts, without which we die of starvation.

Carry your provisions home-after you have made your own selection-and save money.