According to the latest data supplied me by the U. S. Department of Agriculture (February, 1916) the fuel value of protein is about 1,815 calories per pound, that of carbohydrates is the same, and that of fats is about 4,080 calories per pound.

" A pound of wheat flour, which consists largely of starch, has an average fuel value of about 1,625 calories, and a pound of butter, which is mostly fat, about 3,410 calories. These are only about one-eighth water. Whole milk, which is seven-eighths water, has an average fuel value of 310 calories per pound; cream, which has more fat and less water, 865 calories, and skim milk, which is whole milk after the cream has been removed, 165 calories.

This high fuel value of fat explains the economy of nature in storing fat in the body for use in case of need. Fat is the most concentrated form of body fuel".

I have compiled the following table of food values, with special reference to the camp commissariat, from various reports of the U. S. Department of Agriculture. Some of the figures for fuel value, I am informed, were computed by using the factors given above; others were derived from actual determinations of the heat of combustion and the digestibility of the food materials.

Average Nutrients Of Foods

Coffee, " cereal coffee," tea, condiments, and common beef extracts contain practically no nutriment, their function being to stimulate the nerves and digestive organs, to add agreeable flavor, or, in the case of salt, to furnish a necessary mineral ingredient.

Digestibility

In applying the above table we must bear in mind the adage that " we live not upon what wre eat but upon what we digest." Some foods rich in protein, especially beans, peas, and oat meal, are not easily assimilated, unless cooked for a longer time than campers generally can spare. A considerable part of their protein is liable to putrefy in the alimentary canal, and so be worse than wasted. An excess of meat or fish will do the same thing. Other foods of very high theoretical value are constipating if used in large amounts, as cheese, nuts, chocolate.

The protein of animal food is more digestible than that of vegetable food by about 13 per cent, (average), and the protein of wheat is more easily assimilated than that of corn or oats. I quote the following from an article on army rations by Dr. Woods Hutchinson:

" Every imaginable grain, nut, root, pith or pulp that contains starch has been tried out as a substitute for it [wheat] because these are either cheaper in proportion to their starch content than wheat or can be grown in climates and latitudes where wheat will not flourish. Corn has been tried in the sub tropics, rice in the tropics, oats, rye and barley in the north temperate zone, potatoes, sago from the palm, and tapioca from the manioc root.

" Only the net result can be given here, which is that no civilized nation that can raise the money or provide the transportation to get wheat will allow its army to live on any other yet discovered or invented grain or starch. Rice, corn meal, potatoes, sago and tapioca are, of course, ruled out at once, because they contain only starch and nothing to match in the slightest degree the twelve or fourteen per cent, of gluten, or vegetable meat, that gives wheat its supreme value.

" After our first food analyses a desperate attempt was made to substitute corn for wheat, because it contained from five to seven per cent, of protein — called zein — a perfectly good protein in the books and in the laboratoriess but it simply would not work in rhe held. Armies fed on it promptly showed signs of nitrogen starvation; aid, about thirty years later, up came our physiologists with the belated explanation that, though zein was a right-enough protein in composition and chemical structure, only about a third of it could be utilized in the human body.

"Even the purely Oriental nations — the Japanese, Chinese and Hindus — born and brought up on rice, have formally abandoned it in their army ration and have endeavored to substitute wheat for it, though expense and the inborn prejudices of their soldiers have proved considerable obstacles. Troops or nations fed on rice are subject to beriberi and are cured by a diet rich in protein, either vegetable or animal, wheat or meat. Meat and wheat in the ration have wiped out four-fifths of the beriberi in the Japanese army and navy. Those fed on corn become subject to pellagra, which is ravaging our Southern States to-day.

" As for the northern grains, barley, rye and oats, which also contain some gluten, these are all inferior ta wheat—rye and barley on account of their low protein content and considerable bulk of innutritious, gelatinous and gummy materials, which disturb the digestion; and oats on account of the irritating bitter extractives with which their high percentage of protein is combined. Nobody but a Scotchman can live on oatmeal as his sole breadstuff; and it has taken generations of training and gallons of whisky on the side to enable him to dc it".

This is not saying that the grains here condemned are not good and proper food when used in the right combination with other nutrients; but it is saying that neither of them is fit for continuous use as the mainstay of one's rations.

Food Components

Let us now consider the material of field rations, item by item.

Bacon

Good old breakfast bacon worthily heads the list, for it is the campaigner's stand-by. It keeps well in any climate, and demands no special care in packing. It is easy to cook, combines well with almost anything, is handier than lard to fry things with, does just as well to shorten bread or biscuits, is very nutritious, and nearly everybody likes it. Take it with you from home, for you can seldom buy it away from railroad towns. Get the boneless, in 5 to 8-lb. flitches. Let canned bacon alone: it lacks flavor, and costs more than it is worth. A little mould on the outside of a flitch does no harm, but reject bacon that is soft and watery, or with yellow fat, or with brownish or black spots in the lean.